I was planning to run premix, but my car sits for months at a time when I'm at school and can't drive it (4 months at a time). Will the premix settle out of suspension with the gasoline during that time?

 

Check your brand's specs, it shouldn't for relatively short periods i.e. a month but several months might be a problem. If anything keep a 5 gal jug around so that you can pick up 5 gallons of fresh gas and pre-mix that. That should be enough to be safe imo.

 

Most 2-stroke with stabilizers will last 6 months when mixed.