You're a smart cookie HurriPen.

A couple of questions to help you 'fill out' your theory:

1 how would rupees be manufactured?
2 what powers the rupees and what things can they power?
3 why would Hylians, even if they did use rupees as some kind of power source, then use them as a currency?
4 if that was the case. wouldn't it be prudent to see all Hylians using said power source?
5 or if not, wouldn't Hylians who could not use said power source opt for a different type of currency? (namely, everyone who was not Tingle or could not harness the power of the Magic Armor, the only two examples of any 'power' coming from the rupees)