BB's Starting to Recruit at my School - Already Signed FT Offer?

Hey all, any advice is appreciated:

I'm in my senior year at a non-target (target for local banks) outside the US/UK. I signed an FT offer to return for S&T with a TD/Commerz/SocGen type bank not in NY/London. The BB's though this year are starting to recruit at my school, and might be taking 1-2 each. Is there any possibility of leveraging SA OCR to try to lateral to them after a year or two at my current bank? Could this blow up in my face?

My resume as a whole is enough to show I was more or less the top S&T student last year when I recruited, I just didn't get a shot because the banks didn't want to recruit here and I have close to no alumni at BB's for S&T. My current desk is alright, nice people but not very complex products (think repo).

Should I send their HR an email asking about ft opportunities after the info session (chances are someone from HR will be there)? Unfortunately as there are few alumni I have no idea who will be coming.

At the very least I will try to talk to the traders/sales people as much as I can. Any tips for networking at OCR events when you're a senior (and have signed and thus aren't really looking for a job immediately?). Or should I just try to get a FT position and reneg?

Thanks, much appreciated.