I'll echo the sentiments of others that your best options within reasonable commute distance are Ann Arbor and Midtown Detroit. Royal Oak/Ferndale is a good vibrant area for young professionals as well.

Your best bet for meeting internationals is going to be in Ann Arbor, though I'm unsure of what the best way to do that would be. Both AA and Midtown have a good amount of grad students and though both are heavily influenced by their respective schools, they both offer quite a bit more. If you like Ann Arbor but cost is an issue, you can also check out Ypsilanti. It is also a college town [[EMU) and right next door to AA. It's still a pretty decent place to hang out, and a short drive to the things you're looking for.

Royal Oak doesn't have the international population as much, nor the student/grad student population, but it is very young and active. The drive would be much worse than AA/Midtown, but if you're coming from LA, you'll probably be happy with the drive regardless.