James doesn't exist in this What if (read it twice)
We know the Bella in the game was in a sorority (OMG) and she was more like a party girl, so I think she will join the HOTs. Being a year older than Sage, she could be the vicepresident (She is very smart, organized and helpful) instead of Quinn
Being in the same year as Jill, they knew each other, but being one so shy and another a HOTs, it's not impossible they are just friends, no BFF
Bella would have two options to know Tremolo: via HOTs and via Jill so a Bella path will be very different (the romantic triangle Jill/Bella/Tremolo will also start sooner)
In this "What if" the crossroad is Bella being a HOT or being a normal student, two very different options