You should add a tutorial "How to solve all quests in 10 seconds".
However, opposing to AD TienzuStorm, I do not see any abusive potential in this. Resetting your account means losing cards in any way. The rewards were already gotten in the old account, so you don't get anything new by using this (unless you heavily messed up). For testing purposes, the trainer seems much more useful, and overall, it is not so hard making money if you know how to do it right.