I am sorry I really don't see why you need a two tier system and I don't see why you need to give tax information etc.
Or is it a way of stopping some people making money? By making restrictions and forming an elite?
What is needed and surely it is all that is needed is for someone to take responsibility for checking uploads and for the owners to tighten up security on the site. And that surely is what part of their income is for? You don't need a star system you don't need a comment system you just need better security. Maybe you need stronger rules on what can and cannot be posted.
Make it a rule that there must be so many textures in the zip file (or so many tubes etc). Make it a rule that you can only do one upload a day - that will stop a lot of people doing 50 or 60 uploads in a day. Checking on email addresses etc should stop people creating more than one account to circumvent that
I can see the point of making people log in to download. But is everything here for download or is some of it not for download and if it isn't how do you score that for payment.
The one really really nice thing about this site is that it is easy to upload to and it is easy to download from and those are great benefits :)