I would go with a symmetrical airfoil so you'll have good outside capability. It also makes it easier on the pitch trim when you over power.

I did the out thrust testing. The magic number is 8 degrees, from my testing. With this amount, you'll have negligable yaw with an engine out. If you don't use out thrust, consider pull-pull on rudder and a strong servo.

There are a lot of people here on the web who will tell you anything, but there are very, very few who have actually done any testing. The guys who'll tell you to use 0-0 are the same guys who don't use right thrust on a 3D plane. Look at all the really good 3D fliers and their planes have right thrust. I'll admit that 8 degrees looks like a lot. I think Hobbico put in enough out thrust to help, but not enough so it would look unusual to the novice twin flier. If they went to much more they might lose sales. If you do the math, 8 degrees out thrust will cost you less than 1% of your forward thrust (cosine 8).