Yes, rubbing alcohol will work, just add a bit after you've mixed the epoxy 'til it's the consistancy you want (like paint).
Thin CA you can use drop by drop, but as posted above, don't get carried away, don't breath the fumes, and yes it will be marginaly more expensive.
Rustoleum is available at K/Wal-Mart, Lowe's, Home Depot, ect.
Clear (or pigmented) dope is real cheap, already the right consistancy, and fuel proof right out of the container.

Jetts