Thanks, I'm glad you're enjoying it. I'm also slime girl enjoyer, but there's no plans for the MC to become one, though there are a few NPC slime girls that you will encounter.
As far as the Futa MC being permanent, I'm planning on having that entire section be repeatable -- so you can keep revisiting that waypoint to gain XP, rep and Funding and replay the events for the side mission.
There aren't any plans to let her be a permanent futa -- but I may add some events where she could "activate" the futa-ness again, depending on how I decide to resolve that side mission.
I'll have a better idea on what that looks like when I start development on that piece.