Honestly wow.
Thank you so much for your feedback, even made an account for it, I am genuinely amazed.
I would love to discuss with you further and answer everything, but I think it will probably be easier to communicate on Discord rather than here if you want.
In short, I agree with basically everything you said, and everything is on its way, consider that this is very early in development and much more content and polish is planned.
The only thing I don't quite agree is the boss feeling not worth the grind, consider that during it everything has reached max value, and later on you also get resource multiplier to boost your economy even better and it is basically much better to farm during the boss rather than before it.
Maybe make the resource multiplier immediately unlock at the boss, and then make it upgradable.
But overall I agree that especially early on it is too difficult to survive during the boss fight.
I would still love to discuss it further on Discords :)