i would never delete my F2P's...cause they are free and always there should i want to play them.
i pretty much stopped playing F2P in NOV last year with one exception, i log them during DMF to do the opening quests, and 7 days worth of dailies. have gotten more BOAs for alt spec sets this way. they stay logged out at DMF island and when it starts they are already there.
no more:
- BGs....most imbal bracket in the game
- fishing
- exploration
- farming......pets/mounts/rep/anything
- daily cooking/fishing quests
- achieve HO'ing