Would Vincent Vega Have Banged Mia Wallace If She Hadn't ODd?

Despite the obvious chemistry between the two, they would have likely agreed that Vincent getting killed would be less than ideal.

Vincent banging Mia might have altered the course of his life enough that him being gunned down by Butch wouldn't have happened. Of course had Marsellus found out then he may have suffered a worse fate.

Yes. For the reason you just stated. A coked up horny Mia would have been insatiable and irresistible. I also think Marcellus wanted Vincent to bang her. The whole thing was very much a setup date. Vincent had the best intentions of getting out of dodge, but the very fact that he had to give himself a pep talk to walk out the front door shows how weak he was about it.

I wonder if Marcellus still had his suspicions that Vincent banged her since Mia would have still looked messed up from the OD incident and intentionally gave Vincent the assignment to stake out Butch’s house knowing that he would be killed as a result.

I think he probably wouldn't care so much about Mia, but more about Vincent not being someone he could trust since he needed him for a lot of business related - criminal stuff... that was probably the reason why he set them up that evening... and I think that Vincent wouldn't have banged her, he was way too nervous and knew the consequences.

The question is: Would Mia have made the move on Vincent? If not, Vincent wouldn't make a move on her certainly. His worry was about how he would respond to her advances (i.e., would he cave?), but if she made no advances, no worries.

My guess is that Mia would not have pursued a moment with Vincent, even if she had an urge she would have caught herself in time.

Doubt it, in the bathroom he convinced himself to just go home.

Of course not. Time can it be travelled forwards.