Situation 1: The fact that the ball was tipped does not change anything. IF it was a try before, it's still a try. If it was not, it's still not. And, it matters not where the player who tipped the ball was located [inside or outside the arc -- I suppose if the player were out-of-bounds it might have some earing, but I don't think that's possible. Now watch, I'll have it happen in my next game
].
So, you need to decide whether the initial release was a pass or a try, then rule 2 or three points accordingly.
The reason three points is usually awarded on a "lob pass" that enters the basket is because it's difficult to tell whether it was a (ugly looking) try or a (poor) pass, and the generally accepted philosophy has been to award the try (three points). I'd do the same on this play: If the ball had a chance at the basket without the tip, award three; otherwise award 2.
References: 4.39.4A, 4.39.4B, 5.2.1D
Situation 2: Allow the player to play without penalty. If you thought the change (and lack of reporting) was designed to confuse the other team, you could rule this unsportsmanlike. I'd give the T directly to the coach in this instance.
Reference: 3.3.5B