I’ve taken a stand in my life at over-interpreting the greetings and endings of NT letters. Just because “grace” or “peace” or “mercy” show up doesn’t mean we need to flop a big fat concorance on our desk and chase down every possible nuance of a term. I learned this from Eugene Nida long ago: a word has no more meaning in a context than it needs to have.
Especially with hellos and good-byes. But, we should see pregnant meanings in doxologies. Like this one from 1 Peter 5:10-11:

And after you have suffered for a little while, the God of all grace, who has called you to his eternal glory in Christ, will himself restore, support, strengthen, and establish you. To him be the power forever and ever. Amen.

The God of “grace”: the God who embraces cracked Eikons so they can be healed and restored so they can again glow with the gracious presence of God. You may suffer, Peter says, but God is with you: he will restore, support, strengthen, and establish you.
Here’s the kicker for Peter: “To him be the power…”. Nero may think he’s got it, but Peter knows power is in the hands of God. In a sense this sums up the whole letter — Christians who are being put to the test at the hands of powerful people who see nothing but uselessness and threat in this emerging Christian Church in Asia Minor are to learn that God is in control, that God is all-powerful and someday God will make all things right.
At this point Peter says good-bye to to his readers, and tips his hat to Silas for writing this letter so that it reads well in Greek. What he has written is the true grace of God. Stand in it.
Peace to all in Christ, and to you my readers, for sticking with me through this study of 1 Peter.