Thanks for the valuable feedback!
The secondary is totally random, at first it was actually your primary weapon the entire time because we wanted to mess with the idea of gambling to potentially get a totally ridiculous weapon or a really weak one. We then added a primary fire to counteract the truly terrible options that are possible to get (like only 1 bullet every 3 seconds that shoots at a 80 degree angle to the left for little damage). So I think, based on feedback, that we need to polish that a bit more and either communicate how it works better or simply scrap that idea and make it a more consistant experience.
I understand your feedback for the music, we should have went with something more faster paced to match the game better.
I don't think you are especially negative, any feedback is good and yours is very well written and all valid.