If you were to use the template you bought and make a game then distribute it commercially, that would cover its use for your purchase.
If were to want to do that again, you would have to buy the template again.
Game mechanics in general can't be licenced. Anything you learn from the use of the template belongs to you.
The only exception to that might be straight out copying, and pasting events from the template to another project.
Personally I don't see an issue with that, as it's just an ease of use thing.