Will in-ear monitors, even with drum mics, shelter the drummer too much so that he is less aware of the dynamics, as I do not plan on using a drum shield. Maybe it is just better to have the bassist and drummer share the EV ELX115p?
IMO it can go either way. If the drummer is not used to playing with IEM's take some time to work with him to get the levels (in ear and level of the drums in FOH) to fit within acceptable levels. I don't think dynamics are an issue, as even with wedges what you are hearing is not an accurate representation of how the FOH sounds. If the IEM's are properly set up and mics properly placed, I think you will find the results to be quite pleasant.
If the drummer is playing too loud, you can always turn up the drums in the IEM, tricking him into thinking he's playing louder than he actually is. I can say as a drummer, it works. Just make sure you aren't blowing his ears in the process.