If you go GC through TN Visa, that means you can't leave US until GC is processed.
TN->GC, how long does it take? 5 yrs-10yrs?
Not until the I-485 is filed, and then you simply use Advance Parole.
Depends on your category and country of birth.
You obviously did not understand the process, or did not read well. You only need to stay in US during the 3 months it takes to process EAD and AP immediately after you submit I-485. All other times you are free to travel.
Ok I see what you are saying. But to go from TN -> EAD, how long does it take on average?
Depends.
For instance I filed for my AOS in Aug and got my EAD and AP a few weeks later in early Sept. I was no free to travel anywhere I wished. So stuck in the US for a few weeks didn't kill me...
Hey Warlord, what country were you born and what state did you apply from? State that you are applying from makes any difference?