There's definitely a crunchy scene in Boise, but you may have to seek it out at first. IME it's rare to find somebody who thinks you're a freak for home-birthing (there are a lot of licensed, out-of-hospital midwives!), home-schooling, baby-wearing, buying CSA shares, etc.
Just to give you more of an idea of the "crunch" factor....the Holistic Moms Network, Treasure Valley Baby Wearers, and La Leche League in both Ada and Canyon County all active and running. (I'm not sure how old your kid/s is/are). If you're on Facebook (I'm not) you might do a search for these groups. For a long time, the Boise Co-op (a misnomer because they don't involve their "members" in anything) was the only natural foods store, but Whole Foods and Huckleberry's are on their way, and Natural Grocer just opened.
North Boise is the stereotypically crunchy area (old houses, lots of bike paths and parks, etc), but it's also the most expensive. If you're renting and not buying, you may find some affordable options around campus. The East Bench has also become really affordable, and it's centrally located...great if you won't be driving a lot or at all. If we end up moving, we'll be looking to buy there.
I took some classes at BSU, but nothing in the nursing program. The program is supposed to be pretty competitive, though...in a good way. Public transit sucks unless you are living in the North, Northeast, downtown, East Bench, or parts of southeast Boise. If you live too far from downtown, it's really slow and inefficient, at least IME.
There are plenty of bike paths, and the Greenbelt (a paved path that follows the Boise River), takes you right to the BSU campus! I'm vegetarian and know a handful of veg*ns, but I don't know of any organized community. Let me know if you hear of anything.
Hope that helps!