I think it would be better if there was set rules and you have to agree to them before you show up for the fight.
I think we can give Steve a little bit of credit here, of course there are agreed to rules before the girls show up.  But, what do you do when you've got the hotel, 2 girls, and one suddenly starts negotiating rules?  Tough spot really.  Aubrey Black probably got a little leeway because the possibility of her fans buying her video (I don't think there is a crossover market at all in my opinion, but it was worth a shot).  So, I think the hair braiding thing was really bending over backwards to please her.
For Vika, changing the rules was not a good idea right before the fight, but if you were in the position of fight or no fight, we'd all probably compromise.  It's still not very cool though.  
I can almost promise you that Steve discusses the rules and sets them before the day of the matches.  He's a pro.