Warrior – great examples!
A person can do teshuva for anything.
And by the way, there are bigger aveiros than stealing money. Causing someone to do an aveira is worse I think, since you’re affecting the person spiritually and you don’t even gain from it (usually). And I would think that hurting people emotionally could also be considered worse than stealing money.
But one can do teshuva for those things as well. If you kill someone, c”v, you can still do teshuva even though the person can’t be brought back to life. Doing teshuva doesn’t necessarily mean undoing the deed. When it’s possible to do so, you must do so, but when it’s not possible, then that is not a requirement of your teshuva. Your requirement is to do the most that you possibly can to undo the damage – no more and no less.
If you stole money from people and it’s not possible to return it, then you should at least try to ask mechila if possible. If it’s not possible, then you should ask a sheilah as to how to do teshuva.
I have heard some interesting stories regarding people who did really big aveiros bein adam l’chaveiro that couldn’t be undone and they asked sheilahs about how to do teshuva and were given interesting answers. It usually had to do with giving back to the tzibor in some way.
One story had to do with a baalas teshuva who had been oiver on gilui arayos and was told to build a mikva.