Hello Konoi! Thanks so much for playing the demo and leaving a comment. Even to say the demo is difficult to play - that sort of feedback is very useful. I had anticipated that the stat requirements were too high - when I testrun my own games I don't pick up on these things since I obviously know exactly what to aim for. However the new demo is due Monday 25 Feb and I have considerably lowered the requirements so as not to punish players for trying a little of everything. I'll see if I can put a guide download link as well.
Each knight has three main stats yes, but they actually have a fourth as well - literacy, since a squire needs a decent reading/writing skill. Lyall also needs a higher literacy than the other two.
You make an excellent point about a NSFW warning, I'll be sure to put it on the new demo release.
Without too many spoilers, there is definitely a longer plot centred around Errol in later stages of the game, but that's a long way off yet. Initial final game release was August 2018 but I strongly suspect it won't be done by then - more like end of 2018. I do plan to release content month by month though (first on Patreon, then public), rather than making you wait a whole year for a finished product.