That private letter has no authority. Do you accept the infallible decree of Pope Siricius? See
Pope St. Siricius rejects Baptism of Desire

"Not to derogate in any way from the respect owed to Easter [my comment:  when Baptisms were normally done], so it is our will, in the case of infants who can not yet speak on account of their age, or in the case of those would have any kind of urgent need for the waters of Baptism, that they be given aid with all haste, lest it endanger our souls, were each an every one leaving this world to forfeit "both the kingdom and life" (very literal translation here) by denying the Saving Font to those desiring it."

The decree isn't infallible, but there is nothing objectionable about it.  In context, Siricius is correcting what he calls the disorder of baptism being administered at different times throughout the year, in different locations, rather than all new converts being baptized during Easter.  

In the passage cited above, he is clarifying that in the case of infants, or adults in danger of death, baptism is to be administered at once, lest they die without having received the grace of the sacrament and be lost.  

This is still the practice of the Church today, even though she recognizes the possibility that a person can of obtain the state of grace before receiving the Sacrament of Baptism, through an act of supernatural faith and supernatural charity, combined with a desire for baptism (desire alone does not suffice).  

But obtaining the state of grace through extra sacramental means is only a possibility, not a guarantee, and it is impossible to know if it  has happened.  It requires an extraordinary grace from God, with which the person must fully cooperate; and unlike actual baptism, it does not remit all punishment due to sin.

So, it remains the practice of the Church to baptize adults in danger of death, so that they do not "forfeit both the kingdom and life" by dying without the Sacrament that they desired, since their desire for the sacrament in no way guarantees that they made an act of supernatural faith and supernatural charity, which is required for them to obtain the state of grace through extra sacramental means.
 
 

Better recheck the dates.  It was published three year later, not seven, and it was signed by Cardinal Marchetti-Selvaggiani and Cardinal Ottaviani, and approved by  Pius XII.    Pius XII and Ottaviani were still alive when Cushing published the letter on order of the Sacred Congregation of the Holy Office.

Better recheck what I actually wrote.  I said "several", not "seven".  Three years is absurd, and just coincidentally RIGHT AFTER Selvaggiani had died.  Too much of a coincidence for this to be on the up-and-up.  There's absolutely no reason they would have waited THREE YEARS to publish this if this were legitimate.

As for Ottaviani's signature, Selvaggiani was the primary author, as you can see from the letter itself.  Nobody knows how Ottaviani's signature got there, or, if it was a real signature, vs. just ripped off some other docuмent and spliced onto it, if he even read it or was just rubber stamping a bunch of stuff in a stack.

BOTTOM LINE (which you failed to address):  this did not appear in any official publishing organ of the Holy See, not the AAS, and not even something like L'Osservatore Romano.  Consequently, there's zero proof that was even "merely authentic" Magisterium.

Do you also reject the following teaching of Pius XII?

"In the case of other, more necessary sacraments, when the minister is lacking, he can be supplied through the force of divine mercy, which will forego even external signs in order to bring grace to the heart. To the catechumen who has no one to pour water on his head, to the sinner who can find no one to absolve him, a loving God will accord, out of their desire and love, the grace which makes them His friends and children even without Baptism or actual confession." (Pius XII)

I've never seen this quote before and can't find it using Google.  Can you cite the actual source docuмent?

If he said this, I do in fact disagree with this ... just as I disagree with his permitting of both NFP and evolution ... and disagree with his 1955 Holy Week changes.  Pius XII was not perfect and in fact was the watershed papacy that ushered in the era of Vatican II.  Nevertheless, you'll notice that he limits the scope to that of a "catechumen" which also the opinion of St. Robert Bellarmine.  Again, a non-infallible pronouncement that can for serious reasons be respectfully objected to, and I do so object.

I've never seen this quote before and can't find it using Google.  Can you cite the actual source docuмent?

If he said this, I do in fact disagree with this ... just as I disagree with his permitting of both NFP and evolution ... and disagree with his 1955 Holy Week changes.  Pius XII was not perfect and in fact was the watershed papacy that ushered in the era of Vatican II.  Nevertheless, you'll notice that he limits the scope to that of a "catechumen" which also the opinion of St. Robert Bellarmine.  Again, a non-infallible pronouncement that can for serious reasons be respectfully objected to, and I do so object.

It is taken from a general audience given March 5, 1941. Unfortunately, that year's audiences are not available on the Vatican website. The entire speech can be found in the book, Dear Newlyweds, which was originally published in 1961, before bein republished by Sarto House in 2001.  The quote is on page 13 of the 2001 edition.  

Here are a few ways to process this.

1) Had God given him full possession of his faculties, would he have rejected the faith and even become an enemy of it, so that he would have deserved a much worse eternal fate?

2) One of the dogmatic EENS definitions also states that he degrees of suffering in hell vary.  It's not as if a selfless Jєωιѕн grandmother who gave her life for her children is going to be suffering the exact same fate as mass murderer Joe Stalin.  I believe that there are some people in hell who suffer very little given that their natural virtues may offset some of their natural vices.

3) Given that it's possible this man you speak of wasn't capable of making true moral decisions, he may even be in a state of natural happiness like Limbo (given the impairment of his faculties).  Had God NOT impaired his faculties, perhaps he would have sinned a great deal more.  I believe that there are some people in Hell who suffer no more than someone might in this life.

4) God gives EVERYONE what they want.  We see it even in this life.  Some people enjoy going to church and praying, while others prefer to got to raucous debauched parties and find prayer abhorrent.  God will give them what they want.  Their suffering in the afterlife will consist of the fact that what they have chosen doesn't give them true happiness.

5) the Beatific Vision is not something owed to anyone and is not essential to perfect human happiness.  That is why the infants (and other people without the use of reason) are perfectly happy in Limbo, happier than they could ever be in this life.  So apart from this Beatific Vision, everyone receives everything that they want and seek and ask for.  There was a saint who also asked God why He sent people to Hell.  So God asked her to pick a soul in Hell to release from there.  He took the designated soul and put him in Heaven (minus the Beatific Vision I imagine).  That soul simply couldn't take it (kindof like how some people now hate going to church).  He asked out.  Then the saint asked God to at least put him in Purgatory.  So He did.  Then the soul complained that he didn't like that either, and asked to be returned to Hell.  People go where they WANT to go.

At the end of the day, God has more love and compassion than we could ever dream of.  So if you are grieved by the loss of a soul, He is that much more grieved (accidentally speaking of course).

We believe God is love and desires the salvation of all, but there's this thing about free will here, where everyone decides what he wants.

So this person you speak of, trust that God gave Him every possible mercy and that things were arranged so that he would have the least possible suffering in eternity given his free will.  As I said, born into different circuмstances, he may have openly rejected the faith, become an enemy of it, and been a monumental sinner, whereas in his state of impairment he likely sinned a lot less than he otherwise would have.

Thank you
A lot that you have said makes it all easier to accept and understand, but it also makes other things more confusing.
Does the devil care if someone is in a less suffering place in hell?  Is it still a "win" for him? Does he fight and scheme to snatch a soul away from God only to concede  comfort for the soul there? I can only visualize the children at Fatima's vision of hell along with other Saints and visionaries who have been there, and there never is a mention of "levels".  Satan's objective is to steal souls from God, but I'm surprised if he would acquiesce to limbo type happiness in his realm, although I recognize it's not his choice. I guess he may be more restrained in hell than he is here on earth. It's a lot to process.

 Does Satan have full reign of hell in the "kinder" places? I re-read what I wrote and it seem very juvenile , but it's where I am at.