seal scroll, summon scroll, charm, refine, thread, key are the ones with rebate events.

Seal/summon is where you should hold until the max (300 seal, 100 summon) then go. Thread rebate is on rank up, so it makes no difference. key/charm/refine actually have a better return ratio at lower tier rebate, so you should do them "evenly" each month. Thou a caveat on refine is that it usually come along with wish credit event, which encourage burst usage (of advanced refine at least), so you'd have to decide on that.

For level freezing as far as the daily "event" goes:

fox you should tap and exit, deal as little damage as possible. This will still give you the bit of coupon and magatama, but little exp as exp scales with damage.

Quiz gives some, thou not a whole lot of exp, but it also does not exactly provide amazing prizes, so you can opt out of this. It's interesting to note that the reward comes in the mail, so you can do it anyway and decide whether the reward is worth the exp, so to speak, as you look at them in the mail

jin is similar to cat quiz. Thou it's interesting to note that the reward comes in two parts, one completion and one for ranking. the exp reward is in the completion mail, which means you can still do it and receive the ranking reward (from mail) without gaining any exp.

Team instance also gives marginal exp, thou I don't think that would be worth avoiding.