Gratz on ur pick up and ou got average deal on ur aro,
Feed them bloodworm freeze dried is better because it will float, I would put some kinda molly fish or guppies as tank mate on that size especially if it has problem with eating..small aro tends to like competion when feeding.
Ur 75G tank is more than enough for now if all goes well expect ur aro to grow 1 1/2-2 inch a month.
Sounds good. Will it eat feeder guppies? I already have a 5.5 gallon feeder tank setup for my RBP, so I was thinking about adding some of those to the stock of goldfish in that tank. The mollies would work good, if they became a problem for some reason I could move them into the little 2.5 gallon I've it chillin on a desk right next to it.