Here's a cool link I bookmarked a while back. Not sure how accurate it is. http://mycurrencycollection.com/reference/stars/lookup
Maybe not. Gold certificates were called in and declared non-legal tender. And there's also inflation. Even though it might still be worth a dollar, that dollar might not buy the same amount of goods and services in the future... sadly.
Gold certificates have always been, and still are, legal tender. The are not redeemable for gold, though.
I would brush up on your history. Check out Executive Order 6102, which was enforced from 1933 to 1964.
That didn't affect their legal tender status; it just called them all in. Remember that "legal tender" is an entirely separate concept from "legal to own". More to the point, gold certificates weren't legal tender at all before 1919. They didn't need to be--they were redeemable in gold! (But that's why the Series 1922 GCs have a "This certificate is a legal tender..." clause that wasn't on any of the earlier issues.)
You're right, that's not what I meant when I said legal tender. However, I can't see how they could be used as money if they were illegal to own.