Is there a list of chess paradigms some where?  I pick up a few from time to time like ( Develop knights before bishops or in a closed position your valuable bishop is the opposite color to your pawns another one was after a bad move the mentor said I had traded a bishop for a knight in an open position which favors bishops) I would do a little better if I committed them to memory rather than picking them up peicemeal. I realize they are only generalities but...

No list, that I know of.  There are, however, 2 books that cover those chess principles (paradigms) and the authors go into detail and examples of how those principles are put into practice over the booard:

"My System", by Aaron Nimzowitsch

"Pawn Power In Chess", Hans Kmoch

By the way, trading a Bishop for a Knight is know as giving up the "Minority Exchange".  What your mentor was trying to get across is that also when you trade your Bishop for her/his Knight, you are granting your opponent the weapon of the Bishop Pair.  A very powerful attacking piece pair especially in open pawn positions.  It is best described as the 2 Bs hem in the enemy Ns and pawns.  Bishops are usually superior 2 Ns in open pawn positions.  Ns are usually superior to Bs in closed pawn positions.  Finally in the endgame Bs are usually superior to Ns because Bs can cross the board in one move, Ns cannot.  With pawns on both sides of the board, the B will usually outmanouver the N because the B can shift from the kingside to the queenside and vice versa in one move.  The exception is usually when the N can establish an outpost on one of the central squares where it cannot be driven away by enemy pawns.  With pawns on only one side of the board it is usually a drawn endgame.

For lots more see the 2 books mentioned above.

Good luck and hard work in becoming a 'professional gunslinger' (a very strong player.    

I've wondered this too, I keep picking them up in videos. The more advanced you get, the more ideas there are. However, there are also more exceptions.

Thanks for your thoughtful replies. I'll look the books up.