There will be a blacklist, which is keys which are not broadcast. I'd guess WASD is set to blacklist keys by default. You can add or remove keys if you want to.

KC can do mouse clicks, but its not a strength of the program. If you want to use KC for the keyboard stuff, take a look at HKN (Hot Key Net) purely for the mouse stuff; it's a free program. Or alternatively, use HKN exclusively for all of your boxing needs.

I'd take a look at IS Boxer. It is a subscription program, but it has a lot of very strong options/features for boxing. Definitely worth consideration.