I think you're missing,

my interests don't intersect with most of my peers' (see the partying / drinking / buying expensive food stuff above). I'd rather spend time with people who are doing interesting things and who I can relate more with (is this bad?), but I'm having trouble finding such people on my campus.

All your suggestion are good, but it's not worthwhile to put lots of energy in building friendships with people that you don't like.