I don’t recall him saying the part about an invalid episcopacy because all the validly consecrated bishops are dying off.

This would make him an ecclesiavacantist.

What I do recall him saying several times is an acknowledgment that the validity of the  form of the new rite of episcopal consecration is capable of doubt.

Yes, he never said anything like that.

He has spoken about sacrament validity many times, going back to basic Catholic doctrine, you have to have correct matter, form and intention. The matter is easily verified, and the form as well. But as time goes on, the intention is more and more brought into question, hence the problematic validity. This goes for the Mass and various Sacraments including Holy Orders. If the bishop thinks a priest is just a presider-of-the-gathering, and he's "installing" a new "presider" rather than conferring power on a man to offer the Eternal Sacrifice (or at least "do what the Church does"), does he in fact validly ordain a priest? Good question!

But any QUESTIONS regarding validity of sacraments are not so GOOD for Catholics to have, so...

This is a false accusation.  I go to a CMRI chapel and no one has been forced to publicly abjure errors or anything like that.  Newcomers are encouraged to speak to the priests before receiving communion to make sure they are baptized and not in mortal sin.  The priests are very patient as not everyone has a full understanding of the present crisis in the Church.  It isn’t a mortal sin to be confused about some particular point of doctrine.  The only thing that would get you in hot water is to create a scandal or a serious disturbance among the faithful.  Just like any other traditional Catholic chapel.  In that sense, you will not be able to see a difference between an SSPX chapel and a CMRI chapel.  Maybe the most notable difference in appearance is that the CMRI chapel will not have a picture of George the Clown on the wall.

With sedevacantists, "your mileage may vary". However, let's face it. Sedevacantism is a much more black-and-white approach to the Crisis. Sedes should even agree with me here, as they consider it a point of pride they don't "sit on the fence" or "self contradict" as they claim the R&R position does. Sedes don't mess around with unknowns, mystery, or grey areas. The teach that the putative pope isn't the pope, period. They almost always say the Conciliar Church isn't the Catholic Church, simpliciter, period. No nuances. Where does that leave the individuals that attend that church, logically speaking?

Hooray for the CMRI for being "patient" with newcomers and all that, but frankly they are inconsistent with their own doctrinal position when they do so! If the claimed pope (currently Pope Francis) truly isn't the Pope, and the Roman authority is truly NON-EXISTENT rather than just needing-to-be-resisted or disobeyed (which is what R&R teaches), and the Conciliar Church is simpliciter* not the Catholic Church, then one SHOULD be treating novus ordo converts the same as converts from any other false religion. They need baptism (not conditional baptism), renouncement of heresies if they're over 7 years old, etc.

Sedevacantists accuse R&R of being inconsistent, but here we are!

Anyhow, hooray for the CMRI I guess, but I'm still correct about many/most Sede chapels. And insofar as I'm incorrect about the CMRI, I am correct that they are as contradictory as they accuse the R&R position of being. See how wonderfully confusing the Crisis in the Church is? You can't find a perfect position. Not until God intervenes at least.

* Simpliciter is a technical term used by pre-Vatican II theologians. It is Latin for "simply" as in, "No ifs, ands, or buts" or "with no asterisks or nuances".