Heat tape and most UTH definitely heat through 5/8" wood, and as mentioned already, still need to be controlled because they will reach dangerously hot levels for most animals.
Ceramic tile will make your enclosure super heavy. The tiles themselves will be easy to maintain, however you will likely get build up in the grout. I don't know how well the heat will be able to get through the wood and plywood. You shouldn't have any problems cleaning your enclosure as long as you use a smooth wood and seal it well