I've got two tubs set up and they just sit on individual shelves...no rack here, either. It works well.

Any snug fitting lid is fine...but don't assume it'll be all you need. Mine fits very tightly on my big girl's tub and I was sure she couldn't get out....but she managed to pop it off in the middle of the night once. NOW....I keep it clamped shut as well as have a huge, heavy book laying on top of it.

Printed newspaper is fine.

Flexwatt is great...but your best bet is to order it online. Try reptilebasics.com.

Hope that helps!!