I really appreciate the interest in the project.
...
Anyway, please let me now if you are willing to help me that way without any obligations
Great. It is good to see an enthusiastic developer with skills and good idea.
About the english spelling/errors, I personally find non-perfect english (the so-called engrish) a "feature" in games that have a comedic tone. It gives it a charm. So, I really do not mind and if I could give you my two cents, I would not give it an utmost priority right now.
I am not a specialist in RPG MAKER MV, although I do have a experience. Furthermore, I know my ways in programming in general, so I would be glad to help without any obligations, either with some small part of the development or as a beta tester.
Some ideas:
-You probably noticed that people here would rather have a Ren'py game than a RPG maker one, for a myriad of reasons. Ren'py gives the player more freedom in how to control the flow, with rollbacks, quick text skips, and so on. In your case, you choose to put turn-based combat in your game, something which is also not very popular around here, so RPG MAKER is a better choice. Personally, I do not mind either (with or without combat), but if you want to have, maybe it is a good idea to invest some time into making the combat fun and engaging other than a chore, specially if it will be around the entire game. I could help you with that. Not necessarily you have to integrate sex and porn into this feature, but it would be nice to improve it nevertheless.
-UI (user interface) also needs an overhaul. You use standard RPGMV UI right now, but it would be great to customize it. Also, this UI should have a hint system and something that allows us to track the girls' statistics.
-I agree with some here that, as it is right now, the Goblin earns control of the girls too fast. As a wise man once said, part of the fun is not in the destination, but in the travel itself.
-Customizing the sprites a little bit so the girls look closer to their 3D model is also a nice touch.