You said.."I have running water and have misted my terrarium, but the humidity level won't seem to rise"...real non-toxic plants (washed well...both sides of the leaves)will help with the humidity. By "running water" do you mean a dripper or something like a waterfall?
Flaps can be difficult to keep in captivity. They come from such a wide range that its hard to know what the one you buy needs to do well. Carpets are fairly short-lived. Veileds are not the friendliest of chameleons but they are not difficult to keep compared to most chameleons. Although veileds are sometimes able to be handled and some will come out of the cage onto you, they only tolerate the handling....as is true with most (if not all) chameleons. Even when they don't appear to be stressed by the handling or by being out of the cage on you, there is always some level of stress for them during this time.
I can't answer your question about carpets, but most chameleons will not do well with more than one to a cage regardless if its two females or a male and female. One will almost always go down hill....sometimes both.
I recommend a container of washed playsand be kept in all sexually mature egglaying female chameleons' cages. When you are new to keeping chameleons, its easy to miss the sometimes subtle indications that a female needs to lay eggs...so why take the chance?