Hi there grimdawn122. Sorry for the late reply, I've been on out of town and just got this notification.
To answer your questions :
1. Yes, definitely! Getting it polished and bug free is my main priority. I would also like to have a better tutorial in place before releasing to Steam EA as well.
2. I plan on launching themed, free updates. For example, a water update might add ships, pirate characters, and island set pieces. An FPS update might add more weapons, game modes, and enemy types.
For the enemies, you can currently change the model, weapons, and faction, but there are more immediate plans to customize behavior, dialogue, and things of that nature.
3. Absolutely. There are already waypoints in place (see the FPS Tower Defense showcase world for an example), but I'm not so sure about specific animations. The goal is to have each piece be pretty modular. For example, the waypoints can be used for NPC routes, but they can also be used to create railroad tracks, and moving platforms.
4. I've thought about custom quests quite a bit, and I think that feature is farther off. I just can't think of a good way to allow for quests other than "Kill X enemies" or "Reach This Destination", which seems limiting. I may end up adding some sort of scripting system so that advanced users can mod the system to their liking. If you have any ideas for this I'm all ears!
Thanks for the feedback, I really appreciate it! I'm on Discord and the community is pretty active there if you want to keep up to date.