Yes! You can do this sort of thing in PRO Battles. What you need to do is:
Go to the battle mode selection menu (the button with 4 squares on it) Scroll to "Battle List" and click on it Click "Create" Select the map you want to practice on Click on "Custom Options" and check the "Private" box - this ensures nobody can join the battle and interrupt you while you learn. You can still invite friends to join you if you like. And that's all! You can play around with different settings if you want, but the only thing that you really need to worry about is setting the battle to private so you can practice or test things in peace.
Hope this helps, let me know if you still have questions!

Currently, it's still in the testing and planning phase.
Official prices, release dates, etc. haven't been released yet, but the VLog did indicate that this update will be implemented.
 
From what I've heard from the test server, module 2 costs 10 Tk, module 3 100, and module 4 1000, but of course those are subject to change with the actual rollout of the update.
As far as P2W goes, yeah, it is a bit more in that direction, but 110 tankoins for the second and third slots isn't bad with weekly missions. 1000 for the last one is more of a stretch, but achievable F2P with some patience.

Hi!
 
Hunter's electric zap will still disable objects such as Titan's dome, Wasp's bomb, and Ares' energy ball if they were created by a hull with Stun Immunity. 
However, Stun immunity does prevent Hunter's overdrive from stopping tank motion or the activation of another overdrive.
 
Hope this helps, and let me know if I can clarify further.