as far as i understand it
a) yes
b) after a RTO event, you're not going to be taking off full stop untill the brakes are cool enough so that they'll work fully if you have another RTO. But if you did attempt the foolish (i.e. attempting another departure) and then were crazy enough to raise the gear straight away then yes a wheel well fire is a distinct possibility. I'm working on the assumption that you've rejected at speed and not just closed the thrust levers immediately after standing them up due say a config warning or something like that.
As usual i'm willing to stand corrected by those more experienced than myself.