Make Approach to Make EE Membership Site?

Hi Guys!

I’m new to making membership site.

I need your suggestion or approach for a membership website?

The Membership site has protocols and if granted by any protocols below then Members able to view whole content and download files that comes with it

Protocol A - If Member is a Subscriber of a specific Entry, Category or of another User

Protocol B - If Member is of Silver, Gold or Platinum Level (Where should I create the “Level”? in Member Roles, Role Groups or EE Categories?

Protocol C - If Member gets a reward by reaching a specific amount of activities on the website such as commenting, answering surveys and blogging entries

pls reply