For CMP you need to look at the tileset for that area, the tiles are numbered left-to-right and top-to-bottom:
0...15
16...31
32...47
48...63
etc.
and just use that number for the third parameter.
The trick with BSL is the flag I was experimenting with, flag 0200, which executes an enemy's TSC event when its HP reaches zero. I had assumed that BSL caused that to happen, but it's an entirely seperate function. So, just make sure your boss entity has flag 0200 set first.
BOA is used for special animations (or possibly loading the A.I. scripts) of the more complex bosses, the ones that are affected by the bug in Sue's Workshop. That's all I know so far.