Context is pretty plain. God told Peter He was not willing that any should perish. He wanted ALL to come to repentance. Now, who does "all" leave out? He didn't say "All except..."; He simply said "all" !
I believe that Jesus died for all sinners and that all sinners can be saved but your verses in the letters of Peter are not the best selections to prove it. Peter has a certain audience in mind and the primary fiocus of his letter and the application thereof must be the "all" of that audience. Unlike the ministry of Paul, the ministry of the 12 apostles was narrow. Peter and the apostles primary mission was to the "circumcision." That would be to the physical offspring of Abraham through Isaac and Jacob while Paul's ministry was to the whole world, or to the nations, the gentiles..
I am not guessing about that. I have the inspired scriptures saying that clearly. Here.
1 Then fourteen years after (his first trip to Jerusalem after his conversion) I went up again to Jerusalem with Barnabas, and took Titus with [me] also.
2 And I went up by revelation, and communicated unto them that gospel which I preach among the Gentiles, but privately to them which were of reputation, lest by any means I should run, or had run, in vain.
3 But neither Titus, who was with me, being a Greek, was compelled to be circumcised:
4 And that because of false brethren unawares brought in, who came in privily to spy out our liberty which we have in Christ Jesus, that they might bring us into bondage:
5 To whom we gave place by subjection, no, not for an hour; that the truth of the gospel might continue with you.
6 But of these who seemed to be somewhat, (whatsoever they were, it maketh no matter to me: God accepteth no man’s person) for they who seemed [to be somewhat] in conference added nothing to me:
7 But contrariwise, when they saw that the gospel of the uncircumcision was committed unto me, as [the gospel] of the circumcision [was] unto Peter;
8 (For he that wrought effectually in Peter to the apostleship of the circumcision, the same was mighty in me toward the Gentiles)
9 And when James, Cephas, and John, who seemed to be pillars, perceived the grace that was given unto me, they gave to me and Barnabas the right hands of fellowship; that we [should go] unto the heathen, and they unto the circumcision.
10 Only [they would] that we should remember the poor; the same which I also was forward to do.
That is pretty clear cut.
So, Peter writes both his letters to the same audience. Judah was still a nation at the time but Israel had been scattered since 722 BC. They were out of the promised land and considered by God, according to Hosea 1, "not my people," but with a promise that one day they would be called "the children of the living God." To be a child of God requires a new birth into his family and now, since the death, burial, and resurrection, God is keeping this promise, at least in part.
These people are in the general neighborhood of where they were taken. In what we know now as Turkey.
1 Peter, an apostle of Jesus Christ, to the strangers scattered throughout
Pontus, Galatia, Cappadocia, Asia, and Bithynia,
2 Elect according to the foreknowledge of God the Father, through sanctification of the Spirit, unto obedience and sprinkling of the blood of Jesus Christ: Grace unto you, and peace, be multiplied.
What I have bolded and underlined are all provinces, in Peter's day, in Asia Minor. There were many synagogues in those areas.
What made these of circumcision elect? It was the sanctification of the Spirit who indwelt them. He made them children of God by his presence in them. Hiss foreknowledge of these things went all the way back to his words in Hosea.
2Pe 3:1 This second epistle, beloved, I now write unto you; in [both] which I stir up your pure minds by way of remembrance:
1Pe 2:12 Having your conversation honest among the Gentiles: that, whereas they speak against you as evildoers, they may by [your] good works, which they shall behold, glorify God in the day of visitation.
Therefore, I conclude by the preponderance of the evidence that the "all" has the limitation in the primary application that has been presented. However, I will agree with your broader point that it is not God's will that any sinner perish, but all come to repentance.
All of the Jewish Christian epistles are addressed to these same people. James said he was witting to the 12 tribes scattered abroad.