(1) It looks like God who offers forgiveness to all – - who stands graciously ready to forgive.
(2) The relationship has been restored with the repentant. Therefore, a commitment has been made that this matter no longer stands between us – - though forgiveness does not necessarily mean the elimination of consequences.
(3) No.

Question: In comparison to forgiveness what is the difference in our response and attitude toward the unrepentant unforgiven person(s)?

Question: If you don’t forgive unless someone repents – do you try to remember all who haven’t repented and you havent forgiven as to keep up with who is unforgiven in your life?

This deepest sense of forgiving, from the heart, is what forgiveness is that I believe is ALWAYS the biblical calling even of hardened unrepentant enemies though outwardly we may need to demand many consequences because of the offense to include not trusting them, lessening our opinion of them, seeking proper this-worldly punishment for them in ecclesiastical/criminal courts, etc. The teaching you list only provides dangerous warrant to many to say “I don’t need to forgive that person because they have not repented… I don’t need to forgive my wife because she has not GENUINELY repented… etc. etc. etc.” Not biblical, not wise, not the foundation of God’s forgiveness of us in waiting for our repentance on 99% of our sins in thought word and deed (he’d be waiting forever in this life). I AM forgiven for all the sins that don’t even come to conciousness, let alone come to some genuine level of grief and change of mind over them hour after hour day after day.

Piper’s quote only says that while “full work” (I would say the full AIM would be a better choice of words) of forgiveness is forestalled, we still are to desire release of the small debt owed to us even by the most unrepentant enemy just as our much larger debts have been forgiven solely due to God’s grace that came long before any seedlings of our repentance. Here is more from the quote of Piper right after the quote you cite in the sermon on the unrepentant person suggesting we CAN forgive him even when we cannot reconcile/trust him/have intimacy with him due to his lack of repentance:

“”We can still lay down our ill will; we can hand over our anger to God; we can seek to do him good; but we cannot carry through reconciliation or intimacy. Thomas Watson said something very jolting:
We are not bound to trust an enemy; but we are bound to forgive him. (Body of Divinity, p. 581) “”

Calvin is right, see his commentary on Luke 17. I beg you to reconsider your position on this and search the Scriptures, as you would have much influence if you changed your mind. If I am right, it is a very dangerous thing our best Reformed leader/thinkers have done in giving unbiblical excuse to many of our brightest in the evangelical church to NOT forgive, waiting for repentance that will never come and holding onto their petty desires for payback in light of the infinite debts they shockingly expect forgiveness for daily without ever being specifically repentant for or concious of in the ways they fail to love God with ALL their heart, soul, mind, and strength. The multiple dire no-salvation warnings in the Gospels if professing believers are withhold forgiveness (categorical teaching except for the Lk 17 church discipline context) make this too important not to be absolutely sure we’re getting this one right and going beyond the text because we are looking at “well, what is the further AIM of forgiveness”. Being a lawyer in addition to a PCA minister, I can tell you by analogy that is also how we get in trouble with liberal statutory and constitutional interpretation.

I think the citation on Piper is correct. Desiring God just pointed to it off their blog.

If by improperly citing you mean, “out of context,” I didn’t do much analysis of the quote. I think there is enough context given for the quote to stand on its own.

I am always thankful to hear people are thinking deeply about forgiveness. Proverbs 27:17.

“…there are two ways in which offenses are forgiven. If a man shall do me an injury, and I, laying aside the desire of revenge, do not cease to love him, but even repay kindness in place of injury, though I entertain an unfavorable opinion of him, as he deserves, still I am said to forgive him. For when God commands us to wish well to our enemies, He does not therefore demand that we approve in them what He condemns, but only desires that our minds shall be purified from all hatred. In this kind of pardon, so far are we from having any right to wait till he who has offended shall return of his own accord to be reconciled to us, that we ought to love those who deliberately provoke us, who spurn reconciliation, and add to the load of former offenses. A SECOND kind of forgiving is, when we receive a brother into favor, so as to think favorably respecting him, and to be convinced that the remembrance of his offense is blotted out in the sight of God…” Just because forgiveness has reconciliation as its goal does not mean that the definition of ‘forgive’ should be collapsed into what reconciliation is, nor that we are commanded to forgive only when repentance has happened. This is logically inconsistent with the command to overcome evil with blessing and good toward even enemies, is inconsistent with God’s waiting for us chronologically to repent before forgiving for 99% of our sins, and inconsistent with a view of the Greek word apheimi which at its root is a releasing, as in the releasing of a debt for which we desire/seek repayment.