I hate to sound like an uber-cynic here, but when the end comes, I doubt I will regret anything. It is part of my whatever will be, will be philosophy. At least in terms of choosing paths. Life is unpredictable. It is difficult to regret not making a different choice because you do not know if your new direction would turn out worse.
If I will regret anything, it will likely be that God's grace will not forgive my lapses in moral judgment. Everyone has that crisis of faith. We hurt other people simply by existing. How can you avoid doubt with that knowledge?
Otherwise, all things pass away eventually no matter what choices you made. Why waste time regretting them--especially when time is near the end?