Yeah, he will spend most of his day hiding under something, digging or pacing back and forth trying to escape. They have nothing better to do but escape, so you should be sure you have the most 'escape proof' viv that you can provide. They are escape artists.
We have never been bit, but my SO did get a tiny nip once. We feed with tongs to be safe; otherwise he has never actually tried to bite. He hisses a lot and runs, but never bites us.
It's always under debate, but Savannah's don't need UVB exposure like beardies. You may as well save your reptisun for them. Just keep it hot. We have Esham in a 4x2x2 (75 gallon breeder) tank with a big basking light and a 150W (I believe) CHE that stays on all the time. They like to dig and burrow, so a good substrate they can dig in is good. We have used a lot of different things (pellets, plain old dirt, etc.) and we like the coco substrate the best, and it seems, so does he.
The enclosure you have is fine for now, but you will eventually need something bigger. My rule of thumb is the width of the tank should be a minimum length of the lizard's length. So a 4x2x2 would be suitable for a 2' lizard. An 8x4x2-4' enclosure would be ideal for him as an adult. Beware that they can grow up to 5 feet.. We need to upgrade Esham's enclosure soon. We are working on it, though!
viewtopic.php?f=19&t=95301
BTW, I posted a photo thread of Esham earlier, if you want to take a look.