Adjustment of Status - I-485

hi guys,
we'r in NYC.
i ve already got my i-765 EAD card.

my I-485 priority date is 05/22/15 and updated on 07/23/15--"interview is ready to be scheduled". still waiting...

after seeing the other shared experience,like some cases applied in Jan. and just got the interview date in Oct., so i thought my case might not be updated soon.
 
But my current visa status is F1. If the case cannot be finished until i graduate, can i just finish the last semester which is until Dec. and terminate F1, then work with my EAD card?

I'm wondering what is gonna happen if i do that? is it going to be troublesome? Or i should keep my F1 status until i get my green card? (Ps: i don't have 12 months OPT)

is there anyone has the same experience? that could be so helpful.

thank you, guys.