The container size is fine.
The important thing about the enclosure is that the T must be able to find it's prey. Which I am sure you will make happen because it is fun watching them hunt and attack the prey. So no worries there.
With regards to feeders. You can always get roaches instead of crickets. With my first 2 G pulchripes slings I got a small container with about 15 tiny roaches. The Ts enjoyed them. They live longer and don't smell bad.
Keep in mind that some (perhaps all, I am no expert) species of roach especially when they are small, tend to burrow. So make sure your T catches the roach. Even if you have to chase it toward the T. It is a vital source of liquid as well.
With regards to the tarantula.
It will probably burrow and create a new home, so don't worry too much if it doesn't use the hide. Mine just moved the stuff around and basically recreated the entire burrow every day.
But yeah, the photos bring back memories of my 2 little guys. They were so cute and they grow up so fast.
You will enjoy the tremendously, promise