1. Any animal will poop on the walls if it spends most of it's time hanging on the walls. Providing plenty of things to climb on under the lights will lessen the chance of them pooping on the walls but it will still happen time to time.

2. Day geckos are fairly skittish but they usually don't try to leave the tank unless you leave the tank open. I have 2 standing's and they by far have the most interesting personalities.