If someone sees this can you tell me if Flash does anything relevant on this card other than being played at instant speed. The permanent would already be tapped when it enters the battlefield so nothing would happen then?

That's right. Flash doesn't help; you'd need to bring this in before they tap lands for mana. In fact, people could tap things for mana in response to this spell.

How about an alternate wording... something like:

> Each player who tapped a permanent for mana during another player's last turn doesn't untap permanents during their untap step.

Or:

> At the end of each player's turn, permanents controlled by any other player who tapped a permanent for mana this turn don't untap during their controller's next untap step.

Thanks Alex for the help with wording, much appreciated on getting the card to function properly with flash!