2. Software is to hardware as 3 is to 1. Go to school then worry about guns.
3. You may desire to hold off on an AR-15 purchase. See what summer prices bring. Buy a 1st tier rifle for hobby gun prices. Besides now is time to stick toe in the water and get a couple of lowers for under $100 for now?
I know my way around hardware too, enough to be dangerous at least. Did a few semesters as an aerospace engineer before switching to CompSci, but I also know what I don't know.
Too late on not buying a rifle, already ordered an Aero Precision AC-15, but I do want to pick up a cheap lower for funzies soon (either a 300blk pistol/SBR or maybe a longer barrel but still in 5.56).