I think it's great there are mentoring groups that help people get involved in aviation. I've needed lots of advice and counsel in my career and I'll continue to rely on people til the day I retire. The more the merrier...
With that said, are job fairs a good idea? It's easy for a single RJ pilot to jumpseat to one, not so easy for a corporate pilot with a family at home.
Our job is a safety sensitive one. Diversity in the cockpit is a noble initiative, however remember all the customer diversity too in the cabin that may be put at risk if the airline didn't chose the safest pilots to put up front.
Everyone we come in contact with has rights. To hire based on anything else but safety and efficiency is a disservice.