With hardware cloth, you need to be careful about foot and nail damage. Many people use it all the time without any problem (I have it one some of my larger cages). One thing that will help is to provide a large cage with plenty of variety in branches (mounting angle, cover access, etc.) and plenty of foliage without making the cage feel too crampt. By making a large enclosure with a comfortable interior, a lot of chams won't climb the sides at all. Also, be sure to use a wire size that won't catch the nails and tear them out. 1/4" to 1/2" (use appropriate to animal's size) will work well. You'll need to watch out and if your chameleon does start climbing on the sides, keep an eye out for foot damage so you can remove him if needed and treat it. You can get plastic coated wire mesh but it is more expensive. Otherwise, you might consider a material like what repteriums are made of as this will be easier on their feet. Unfortunately, if you have feeders loose in the cage, they can eat through this material. There are pros and cons to each so you'll need to decide what works best for you.
You can't really just ask for a number of crickets per day. Different animals have different metabolisms and needs. Further, what you are feeding the crickets will have a drastic effect as well. These articles (and others in the article reference section of
www.chameleonnews.com) may help you with understanding their needs:
http://www.chameleonnews.com/year200...n_sept_02.html
http://www.chameleonnews.com/gutload.html
With regard to temps, you need to setup a cage with an effective temperature gradient (
http://www.chameleonnews.com/year200...gradients.html). I prefer with all my chameleons to allow them access to temps in the mid to low 70s with access to adequate basking spots thereby allowing them to decide what they want. You should gain a pretty good idea how comfortable the cham is with the temps based on how much it is basking, etc.
Chris