1. The difference btw a pharm intern and a pharm tech?
As I have very recently learned (after moving to New Jersey) different states have a very different definition of what an intern is. In many states it's someone who is in pharmacy school, in some it is just someone who is currently on rotations, and in some it is someone who has a pharmacy degree but doesn't have enough hours to be eligible for licensure, and so while getting those hours they are called interns.
Again, depends on the state. For an intern, some require being already in pharmacy school (aka after the first day of class as opposed to merely being accepted), some can register as interns after first year of pharmacy school, and some have no intern registration at all, and it's up to your employer what they want to call you. As far as techs, also a large amount of state-to-state variation. Some states register techs, some dont. Some require board certification for the tech status, some dont. Some have internal exam and CEs, some don't. Some only require certification for techs who work in the hospitals. A lot also depends on the institution's policies.
Interns usually make more than techs, and hospitals generally pay more than retail. Plus, there is geographic difference - San Diego vs. middle of North Dakota. I would say that a certified tech is anywhere between 8-12 dollars in retail, and 14-20 in a hospital, while an intern is somewhere 10-15 in retail and 15-25 in a hospital, but it's hard to say.
See above.