Character max is 500. Equipment max is 400.
Here's one I just learnt today....
Do NOT level up (or have full stamina or Raid Points) just before 12:00 UTC time when they do Maintenance (normally Tuesdays and Thursdays it seems).
If they are out for two hours like sometimes, that is 40 Stamina points lost (that you would not have regained) and 3 Raid Points lost (that you would not have regained).
Since this has come up a few times, I'd like to add this to the compendium of info for beginners:
Exchange tickets cannot be saved until the next unit pool update (typically when a new event begins and the featured girls from the previous event are added to the general pool), and sometimes expire well before the pool update.
DO NOT TRY TO SAVE EXCHANGE TICKETS.