Very short-term memberships

How do I set up S2Member to handle sales of 3-day memberships, giving each paid visitor access to a few special pages and preventing their access when their 72 hours have passed? I’m a non-programmer WP user. Do I need someone to write code?

When you create your paypal buttons (s2memer -> paypal buttons -> select level), in the large dropdown box select paypal (buy now) One Time (for 3 day access, non-recurring, no trial).

Then when you generate your button it s2 will control all of that for you.

Hope that helps,
Dave

Can I set it up so s2Member prevents or warns a forgetful visitor with a current membership from buying another overlapping membership using the same username and email?