I'd think that doing to bug-training is rather flawed anyway, for example, if you keep hurting yourself to get HP, then curing yourself, then eventually you'll find yourself not owning enough gil to heal at the inn. Cosidering that the inn price is dependent on your healing needs, you'll need to do a lot of "proper" battles to get the money, which just uses up the time that you'd use otherwise. Also if you keep using the select-cancel thing with magic, then you will not gorw sufficient MP to keep up with your magic levels