1. Yelena would be willing to go on an away mission, and wouldn't need any special convincing.

2. She excels at intelligence gathering, deception/manipulation, and stealth and physical infiltration. She's also very good at violence, and will join in on combat if she's needed, but given the number of heavy hitters around, she's probably more use in the rogue slot unless/until things go completely sideways or her cover gets blown.