welcome to the site.. i will start by saying that pretty much any axiom speaker you buy, you will be happy with.
with what you have said, i think you are on the right track in your decisions. if it is a smaller space, and you are not the kind of guy to really crank it, then the smaller bookshleves are the way to go.
1st- if you are gonna go with a 'cheaper' sub, then i would maybe look at the M3's instead of the M2's. i know i have seen posts from many people that are happy with that dayton sub from parts express.. it is no means on the level with an SVS or HSU, but for your requirements, i am sure it will work fine. i just think the M3's will fill that mid-range void a litle better than the M2's. and you can use a bookshelf as a center channel, its been done lots of times. results can be mixed. the shielding of the VP100 will help with placement issues, but if you dont think that will be a problem, then an M3 or M2 will do just fine. the QS4's are great speakers, no worries there.
i dont know much about that pioneer receiver, but basically, anything with some good inputs/outputs and around 60-80 watts per channel will do you well.
good luck in your decisions, and good luck with graduation!!
bigjohn
