Hello Jarron,
Church drummer and some time church sound tech(did a 20 year run at FOH at previous church) here. As a drummer, there's no way I want the responsibility of mixing of any kind(well, except my aviom settings... but thats pretty much set and forget)while I'm playing drums. I'm too busy keeping steady time, watching my dynamics(playing softly when required, loud when required and some times not at all) and doing my best to put an emotional feel into the music.
Hopefully, your PA system has a sub-woofer to give that kick drum it's presence. At our church we currently use a Shure Beta 52 in the kick, SM57 on the snare(though its run at a pretty low level on the fader) and a pair of Rode NT5's as overheads. I've ran sound for church events outside of the sanctuary with the same gear minus the SM57 and it sounds fine.
My two cents are let the tech sub-mix it at FOH as mentioned, put up some plexi drum shields(with some absorptive material or panels on the lower third or so of the inside and maybe on the wall behind the kit) and buy the(or have him buy)drummer some light weight sticks. My current fav's are Vic Firth AJ5 jazz sticks. Light weight will carry less inertia which is especially important when making a fast move to a cymbal with out blasting everyone out. I also use Vic's SD5 echo sticks.
Hopefully you can also get the drummer set up with headphones for monitors. If he's playing too loud, increase the drum kit level in his headphones and he might play softer thinking he's really loud(psycho-acoustics).
Much success to you.
Eric