Best Sources of Exp/Drop Buffs

You can get 1.3x EXP as a random additional reward after doing Resting or whatever it's called, if not Resting than something very similar.

Yes it comes from resting. I've done a lot of testing with this, and you always get the 1,3x buff if the reward is special (note red text at login screen). The buff will last for 10 min for each hour that you put your char in part time job for. However if you do 1 hour and 1 min, it will be 20 min duration instead of 10 min. The last option of part time jobs will ALWAYS give you a 1,3x drop coupon (forgot the name, one to the >>>). Both of them act like family buff or the free 1.5x coupons, so you cant stack them.

Got the IA the other day, isn't it 13%?

Pots are 10%/15%/20% and align with the normal potential tiers.

Yes its 13%