Oh God... I remember watching ProtonJon do a secret level in Kaizo Mario World, and let me just say I'm REALLY not looking forward to this hack...
Anyways, I'll look into them. Honestly, it's going to be really easy finding shop prices. Removing the heart containers might be kinda hard though.
Not at all. In fact you could replace the heart containers with somthing like a 5 rupee reward or somthing. HC's that spawn after the boss are events like anything else and can easily be modified.