i would recommend you finish it, you're really quite far anyways.
spoiler
not using a baked good to skip muffet isn't really that big of a deal, it's just supposed to be a joke because most players wouldn't buy anything at the bake sale anyways. i didn't do it on my first playthrough, either; i believe all the items there are purposefully overpriced so that it's more likely for you to encounter the boss battle on your first playthrough.
obviously if you're not that great at bullet hell i can understand it being a hard time, but i wasn't that great either (never really played any bullet hell before) and i got better enough that it was a reasonable challenge but not too frustrating over the course of the game. i thought the different mechanics used within the bullet hell JRPG framework were clever throughout.
in terms of writing, it's really a story totally focused and revolved around the characters. if you don't like the characters you're not going to have a good time, but if you do you'll have a great time.
as far as ideology it's obviously very liberal but for a reason slightly different and/or deeper than what you describe: after all, the monsters in the story could reasonably be interpreted as a nation exploited/oppressed by the humans, which is good. but, the story takes place from the perspective of that nation (with the exception of the main character, who is just an insert) as opposed to the fact that the vast majority of "gamers" come from an exploiting class (white, men, etc). furthermore, as you touch on, the story posits that peace by all means (literally pacifism) is the way to resolve that exploiter/exploited contradiction, which is of course deeply, deeply liberal.