Can you get released early from an active duty contract to go G2G non-scholarship option?

Being released from active duty into Cadet Command is the outcome of being selected for G2G. If you choose the non scholarship route, you are eligible to enlist in the Guard or Reserves under Simultaneous Membership Program.

Yes you can. It does go through both your chain of command and the ROTC program. Basically you get discharged for the purposes of Green to Gold.

You most definitely can. That's exactly what I did. Most units will process it like a school drop, but the paperwork is obviously different.