Stuball. Welders along the entire hinge line is probably too much. I made that mistake on my Edge when they first came out. It was a bit dodgy but what I did was bent the surface to stretch the glue and very very
carefully ran the tip of a #11 blade along it. Going by feel and sometimes it would take a few light passes until I could feel that I had reached the foam but not cut through it. The tape you have at the ends should be enough so anything in between that is just stiffening your hinge in my experience.
2s or 3s!!! that's the beauty of the stock power set. Change the prop, change the pack and change the beast your flying
it really doesn't matter as long as your having fun and with the Pitts that's a given.