The per transaction load is $500. Not sure about the per day/per store load. I started out small and ramped up as they got to know me. They're use to me doing $500. However, I will do back to back $500 loads at the one store.
It really depends on the CSR. The one I do 1k with is young, works weekends, training to be a manager, but eventually will be starting his own business. I imagine he'll do well if he learns how to manage his money.
I go early in the morning. I also load small cards but get out of line if someone comes up. I've started buying things too. Their cleaning supplies are cheaper. At one store they really loosened up when they saw me buying some grocery items. They had Libby's vegetables 3/$1 on sale, so not a "waste" to pick up some.
We have some new CCs coming and can load Serve aftet the first. One of the weekends when he's working, I'm sure he'll let me experiment and see if we can do the max $2500. However, it's not something I would routinely do at one store. The nice thing is you can use OV GCs.