Class configs for FA are made with .mbch files. You can check the wiki for more in-depth info, or message me on steam I can help you/do it for you.
I'm pretty sure loading screens are saved as pictures and then are referenced to be shown.
You forget that now people realize SBD Blast Cannon is good, they will use it more often, leading to imps victory. Do you think giving rally to the B1's would be a better solution?