I don't know how bosses work but having to deal 5 million damage to a boss to get a skill point is pretty nuts. If prestige resets skills then you should really lock bosses until players have a high level of prestige to actually fight them and make them worth doing...
You don't even get money for hitting a boss during a boss fight, whatever you go in with is what you get. Doesn't feel like this was effectively play tested.
Also, power ups only lasting 30 seconds that you can use once?! With a totally patronizing "Use them wisely." Yeah, the wise choice is to just not use them because most of them are entirely useless.
Using the double gold is the only one that makes sense and really, just get to level 20, double the gold, prestige and keep doing it until you can get to level 100 extremely quickly... What a pointless mechanic..