H1B, GC to F1

[H1Tracker]

My 6 year quota of H1b would expire in 1.5 years. I have started GC PERM process from my company last month. Next year I have plans to join a business school for which I understand,
I would have to change my status to F1.

1) To my knowledge, having imigration intent will be an issue in getting F1. Is it possible for me to change my status to F1 if I stop my GC process before I start with I140.
2) There are several milestones in the GC process. If I m willing to wait for time, say 2-3 years, will I be able to join a school (with/without F1) after reaching one of these milestaones.
3) Is there a way I can join school without affecting my green card process.

[DMX17]

Non-immigrant intent is a fascinating idea but let me now propose something that is open to debate...

Let's say your PERM and I-140 are approved for your old emplyer before you go to F1 status and now you are on a long waititing list (assuming India/China).

Now in your head, you immigrant intent somehow fades and a non-immigrant intent is realized. You go back on F1 for 2-year to an MBA and get a job upon graduation with MBA.

Now again, you have a immigrant intent, your new employer files for GC again with PERM and you capture the old PD on this I-140. You are back on track.

I mean immigrant/non-immigrant intent is not something which shows up on your head.