Mix & Match Power Packs
I think it would be easier to personalize SuperBetter if you could take power ups, bad guys, and quests from any power pack and add the to your To Do list. Right now, if you add/delete a power pack, you take on all the facets of the power pack, even if some of them aren't challenges for you, and then when you delete your power pack, all of the facets are taken off your to do list, even ones you might still want to work on.
Obviously you can recreate these yourself later, but it would be nice if you could simply hit some sort of add button next to particular facets of a power pack you might like.