Do I have a legit attack:

Is this endgame (resulted from the above) drawn with best play?

In the top diagram the black's rook is trapped so.. it's not so good for black.  White is defended.

In the bottom diagram is a long way from over, but black should be playing for a win.  The white knight can't compensate for passers on opposite sides.

I would definitely take my chances with black in the second position.  White has to save his knight, and doesn't really have a lot of time to stop the pawn from queening.  Without playing it out, I suspect the knight gets traded for that passed pawn, and then it's a rook and 3 pawns vs. a rook.  I'm pretty sure black is winning that one.

I tried a few things for black in the first position, and I don't really see anything good coming out of that one.  I believe white is winning.  Your attack wasn't ready yet.