I have never heard of a Cham loosing a nail because of a screen cage. I've never used anything but screen for my adults and babies, besides the older they get it seems like the less and less they walk on the sides of the cage. Also the more stuff you have in your cage like plants, vines, and...
First off I'll help you save some money, dont ever buy a basking bulb from a pet supply store, they are so over priced. Just buy a regular light bulb with the same watts as the current basking bulb, that'll save you at least ten bucks. As far as using foil, I've never done it but I've seen...
Good to hear your gathered much needed info before diving in right away. I've seen way to many people get a Cham without really knowing what they are getting into. I havent seen your cage so I don't know how it's set up but if your new Cham is shy then you should put more plant coverage through...
Noting is the best thing to put on the floor, chams don't need anything and can eat the bedding and become impacted. If you want you can put down paper towel to make it easier to clean.
Depending on what it's up aginst you can use zip-ties which seems to work very well and keeps it locked in place. You can also use fishing line and it works good too.