I will go with St. Pius X on this one.

If Protestant, Mormon, Witness, Adventist, Muslim asked me if they can be saved, I will respond, "No, you will be damned." The nuances of Augustine and Pius IX are too much to discuss with those outside the Church. The only proper thing to say is they will be damned.

How can anyone of them in America say I am invincibly ignorant of the Catholic Church and its teachings? Give me a break. There is a Catholic Church practically in every town in America. So for all practical purposes they have no excuses as they flush their unused and out of date contraceptives down the toilet.

It could be that my mental wiring tends to take statements literally.

But assuming that Augustine and Pius IX did in fact nuance this (I'm leaving aside for the moment the Feeneyite arguments that say that such nuances don't exist, since you seem to disagree with them) why would it be wrong to instead say something like "You'd most likely be damned?" 

St. Augustine never "nuanced" this. He is very clear that no one is saved unless they are Catholics in a state of grace.

What am I missing here?

//[color=rgba(0, 0, 0, 0.87)]1. The[/color][color=rgba(0, 0, 0, 0.87)] [/color]Apostle Paul[color=rgba(0, 0, 0, 0.87)] [/color][color=rgba(0, 0, 0, 0.87)]has said:[/color][color=rgba(0, 0, 0, 0.87)] [/color][color=rgba(0, 0, 0, 0.87)]A man that is an heretic after the first and second admonition reject, knowing that he that is such is subverted and sins, being condemned of himself.[/color][color=rgba(0, 0, 0, 0.87)] [/color]Titus 3:10-11[color=rgba(0, 0, 0, 0.87)] [/color][color=rgba(0, 0, 0, 0.87)]But though the doctrine which men hold be false and perverse, if they do not maintain it with passionate obstinacy, especially when they have not devised it by the rashness of their own presumption, but have accepted it from[/color][color=rgba(0, 0, 0, 0.87)] [/color]parents[color=rgba(0, 0, 0, 0.87)] [/color][color=rgba(0, 0, 0, 0.87)]who had been misguided and had fallen into[/color][color=rgba(0, 0, 0, 0.87)] [/color]error[color=rgba(0, 0, 0, 0.87)], and if they are with anxiety seeking the[/color][color=rgba(0, 0, 0, 0.87)] [/color]truth[color=rgba(0, 0, 0, 0.87)], and are prepared to be set right when they have found it, such men are not to be counted[/color][color=rgba(0, 0, 0, 0.87)] [/color]heretics[color=rgba(0, 0, 0, 0.87)]. Were it not that I[/color][color=rgba(0, 0, 0, 0.87)] [/color]believe[color=rgba(0, 0, 0, 0.87)] [/color][color=rgba(0, 0, 0, 0.87)]you to be such, perhaps I would not write to you. And yet even in the case of a[/color][color=rgba(0, 0, 0, 0.87)] [/color]heretic[color=rgba(0, 0, 0, 0.87)], however puffed up with odious conceit, and insane through the obstinacy of his[/color][color=rgba(0, 0, 0, 0.87)] [/color]wicked[color=rgba(0, 0, 0, 0.87)] [/color][color=rgba(0, 0, 0, 0.87)]resistance to[/color][color=rgba(0, 0, 0, 0.87)] [/color]truth[color=rgba(0, 0, 0, 0.87)], although we warn others to avoid him, so that he may not deceive the weak and inexperienced, we do not refuse to strive by every means in our power for his correction. On this ground I wrote even to some of the chief of the[/color][color=rgba(0, 0, 0, 0.87)] [/color]Donatists[color=rgba(0, 0, 0, 0.87)], not indeed letters of communion, which on account of their perversity they have long ceased to receive from the undivided[/color][color=rgba(0, 0, 0, 0.87)] [/color]Catholic[color=rgba(0, 0, 0, 0.87)] [/color]Church[color=rgba(0, 0, 0, 0.87)] [/color][color=rgba(0, 0, 0, 0.87)]which is spread throughout the world, but letters of a private kind, such as we may send even to[/color][color=rgba(0, 0, 0, 0.87)] [/color]pagans[color=rgba(0, 0, 0, 0.87)]. These letters, however, though they have sometimes read them, they have not been willing, or perhaps it is more probable, have not been able, to answer. In these cases, it seems to me that I have discharged the obligation laid on me by that[/color][color=rgba(0, 0, 0, 0.87)] [/color]love[color=rgba(0, 0, 0, 0.87)] [/color][color=rgba(0, 0, 0, 0.87)]which the[/color][color=rgba(0, 0, 0, 0.87)] [/color]Holy Spirit[color=rgba(0, 0, 0, 0.87)] [/color][color=rgba(0, 0, 0, 0.87)]teaches us to render, not only to our own, but to all, saying by the apostle:[/color][color=rgba(0, 0, 0, 0.87)] [/color][color=rgba(0, 0, 0, 0.87)]The Lord make you to increase and abound in love one toward another, and toward all men.[/color][color=rgba(0, 0, 0, 0.87)] [/color]1 Thessalonians 3:12[color=rgba(0, 0, 0, 0.87)] [/color][color=rgba(0, 0, 0, 0.87)]In another place we are warned that those who are of a different opinion from us must be corrected with meekness,[/color][color=rgba(0, 0, 0, 0.87)] [/color][color=rgba(0, 0, 0, 0.87)]if God perhaps will give them repentance to the acknowledging of the truth, and that they may recover themselves out of the snare of the devil, who are taken captive by him at his will.[/color][color=rgba(0, 0, 0, 0.87)] [/color]2 Timothy 2:25-26
[color=rgba(0, 0, 0, 0.87)]2. I have said these things by way of preface, lest any one should think, because you are not of our communion, that I have been influenced by forwardness rather than consideration in sending this letter, and in desiring thus to confer with you regarding the welfare of the soul; though I believe that, if I were writing to you about an affair of property, or the settlement of some dispute about money, no one would find fault with me. So precious is this world in the esteem of men, and so small is the value which they set upon themselves! This letter, therefore, shall be a witness in my vindication at the bar of God, who knows the spirit in which I write, and who has said: Blessed are the peacemakers: for they shall be called the sons of God. Matthew 5:9[/color]
//

http://www.newadvent.org/fathers/1102043.htm

This is how I did it: Copied and pasted to a word docuмent, clicked on "keep text only", then copied and pasted here:

To Glorius, Eleusius, the Two Felixes, Grammaticus, and All Others to Whom This May Be Acceptable, My Lords Most Beloved and Worthy of Praise, Augustine Sends Greeting.
 
Chapter 1

1. The Apostle Paul has said: A man that is an heretic after the first and second admonition reject, knowing that he that is such is subverted and sins, being condemned of himself. Titus 3:10-11 But though the doctrine which men hold be false and perverse, if they do not maintain it with passionate obstinacy, especially when they have not devised it by the rashness of their own presumption, but have accepted it from parents who had been misguided and had fallen into error, and if they are with anxiety seeking the truth, and are prepared to be set right when they have found it, such men are not to be counted heretics. Were it not that I believe you to be such, perhaps I would not write to you. And yet even in the case of a heretic, however puffed up with odious conceit, and insane through the obstinacy of his wicked resistance to truth, although we warn others to avoid him, so that he may not deceive the weak and inexperienced, we do not refuse to strive by every means in our power for his correction. On this ground I wrote even to some of the chief of the Donatists, not indeed letters of communion, which on account of their perversity they have long ceased to receive from the undivided Catholic Church which is spread throughout the world, but letters of a private kind, such as we may send even to pagans. These letters, however, though they have sometimes read them, they have not been willing, or perhaps it is more probable, have not been able, to answer. In these cases, it seems to me that I have discharged the obligation laid on me by that love which the Holy Spirit teaches us to render, not only to our own, but to all, saying by the apostle: The Lord make you to increase and abound in love one toward another, and toward all men. 1 Thessalonians 3:12 In another place we are warned that those who are of a different opinion from us must be corrected with meekness, if God perhaps will give them repentance to the acknowledging of the truth, and that they may recover themselves out of the snare of the devil, who are taken captive by him at his will. 2 Timothy 2:25-26
.
2. I have said these things by way of preface, lest any one should think, because you are not of our communion, that I have been influenced by forwardness rather than consideration in sending this letter, and in desiring thus to confer with you regarding the welfare of the soul; though I believe that, if I were writing to you about an affair of property, or the settlement of some dispute about money, no one would find fault with me. So precious is this world in the esteem of men, and so small is the value which they set upon themselves! This letter, therefore, shall be a witness in my vindication at the bar of God, who knows the spirit in which I write, and who has said: Blessed are the peacemakers: for they shall be called the sons of God. Matthew 5:9

Only those very few non-catholics, who as it says above, are “anxiously seeking the truth” are not heretics.  It’s hard to tell who that is, exteriorly, but God knows the hearts of these people, as He said of them in the parable of the Good Shepherd:  

And other sheep I have, that are not of this fold: them also I must bring, and they shall hear my voice, and there shall be one fold and one shepherd.  (John 10:16)