Thanks for the post!
I actually notice the same thing and like the voices as well, but I have gotten a few negative comments on the voice acting over the course of the First Access. Unfortunately, I don't have a lot of budget to be able to redo the current voices and/or add more voices to the game. We've been wanting to add the text dialog for a while and I do have writers that are contributing to the project who were excited to work on that aspect.
We have on our list to improve the ambient sounds in the game. Perhaps we should do this first before making the final determination on the voices?
I'll definitely try to see why overwatch is slower than other actions.
Yes, customizing team members will return at some point. There wasn't an obvious place for it since I was just assigning random recruits now rather than using the "store" but I think this is a solvable problem.
Hiring the merc is only required for the tutorial (first objective). It just needs 3 characters in order to work correctly. We'll probably upgrade it at some point and change that but for now it kind of needs to be that way for new people.