Warning: Some SSR evolution tickets are actually UR evolution tickets. They show up correctly in the right panel of the evolution window.

You don't lose anything switching between church/temple.
Looting is random, hitting the button just speeds it up.

Some dungeons unlock when you to beat all the battles in previous dungeons (1-star). Some battles require you to get stars to unlock. The progress bar in the top left shows how many battles you've unlocked.