HttpS IssueS...

[DrByte]

How do I get users to be able to tell a friend, or read/write reviews WITHOUT registering?

You'll have to write custom code to do that. Zen Cart requires registration for those activities because otherwise those forms get spammed aggressively.

And then further, how do I integrate the HTTPS so that pages aren't dieing?

There are tons of handy FAQ and Tutorial articles at https://tutorials.zen-cart.com (see Tutorials link at the top of this page).
Searching for "https" there brings up the answer to your question as the first result.