You are very much welcome, haha~ I think there's always been monstergirl-lite things out there, but not many that focused on the femdom aspect that MGQ and Violated Hero brought about, so I took it upon myself to try and fill that void. So I'm glad you enjoyed it!
I can try my best to answer your questions, though as you say in some cases I can't fully answer everything because of spoilers and such!
I can't say much regarding Matt, though your theories are certainly unique, haha. The second chapter won't explicitly say much about him personally, though will probably make his backstory a little bit more obvious as it unravels with everything else going on around him.
"You mentioned humans, does this mean that we will get less Monstergirls? have we met all the Monsters already?"
With the capital city becoming a large, central focus of the second chapter, it was inevitable that humans would join the cast eventually. In most cases they're side characters (though this doesn't mean they won't have scenes with Matt!) but some humans such as the Queen are major characters in the plot. I'm trying to avoid filling up the cast with humans too much as I know monster girls are the main appeal, though do need a few to help the city feel lively and not just have everyone have a generic sprite/no sprite at all. I'm trying to strike a balance so that the new monster girls added will outnumber the humans added, so have no fear!
"Regarding the humans, will they be human to start with but actually be monsters when you get to know them or pursue their story?"
Welll, I don't want to spoil too much. But yes, some humans might have more to them than meets the eye. It is a monster girl game after all~
"Will we be able to actually favour a certian Monstergirl/character properly and favour the monsters over the city as well?"
While chapter one was fairly linear to a large degree with only a few branching points that ultimately really only determined the h-scene you were going to get, I'm aiming to give the player a bit more freedom in what they do/say--with the aim being that possibly in the third part Matt will be left with two major branches in the story.
Thank you very much for the questions~ Hopefully you're happy with the answers, since I had to keep vague for some parts, but I'm sure you understand. ; P