I'd like some info on editing Heatman and Quickman because there's none in the word file.
Honestly no offense but the best way to find those info is to learn to do the searching yourself.
MM3's RAM map should be available. During a fight with Heatman or whatever, based on the ram map you can find the addresses used by the object. For instance according to datacrystal, ram address $0360 to $037F = X Coordinate, so one of those will be the object's X coordinate. You can easily guess it and freeze or change it to make sure.
Set a write breakpoint on that address, that will open up the debugger, which in turn leads you to the relevant rom data. From there, learn how to use the debugger and to read 6502 assembly. It's not hard, if I'm learning it without no prior programming knowledge, anyone can.
Make sure that the breakpoint sent you to the boss's code, and not a routine that a boss uses which is probably used by many other things (not a good idea to change that just yet). If you're seeing a routine you can "step out" which brings to the point which called it.
At that point the easier edits is to find a bunch of LDA addresses and to mess with them. Once you get the hang of it and a better understanding you can try replacing a routine by another, and then more, much more.
Do this for different ram addresses (coordinate, speed, etc)
Basically base yourself on whatever MM3 doc there is and on 6502 assembly tutorials.
Make sure to take notes of everything you're doing. Always set back to default whatever you changed that didn't end up interesting or useful. Make backups.