SilverfireSage
Explorer
Don't forget Druids. Wildshape twice between every short rest. That's how many bonus hit points, plus the fighting form and spells, for Moon Path druids. Absolutely hysterically broken. DruidZilla is here and all your base are belong to him.
As a DM, I don't really see allowing my PC's very many options to do short rests during the day. Maybe twice during really big dungeons, and only at specific times. After all, the short rest is a freaking HOUR and how often can you just sit in a monster-ridden dungeon for an hour without anything attacking you?