Your answer to the first question is Yes. Orthodoxically, leg spinners are wrist spinners unlike off spinners who are finger spinners, so it does not matter whether batsmen are right or left handed. But yes, they will take the deliveries as off-spin for a righ-handed batsmen. Second question is a bit tricky as very rarely such situation arises. I wonder, if that has ever happened. When a batsman is out, the ball is dead by default so it cannot do additional damage to the batting side. However, if the timing is same, both can be given out and/or benefit of the doubt can be given to one.