Good idea but will really kill competive battling.
Perhaps introducing a new class, such as STM? (Super--TM)
The current tm's would be classified by power and ability. Hyperbeam would be a STM, as would Toxic. While your weak bullet seed would be a regular tm.
Regular tms can be reused as much as you like but your STMs would be one time use.
Examples of STM's would be hyper beam, solar beam, overheat, toxic, any hp recovery moves, any ohk moves, and certian other moves.
Edit - Having the elemental hypers as tm's would be nice.