Wood doesn't ignite until over 400 degrees....so it's not a fire hazard. Hopefully your heat mat isn't getting that hot

I do suggest looking into thermostats though, the dimmer are okay for temporary basis and they constantly have to be adjusted....so unless you can check it 3-4 times a day it can be dangerous for the snake. I'd get thermostats for the heat mats and use the dimmers on any lights for the enclosure instead. 75 watts is probably very high and making it very hot. I suggest CHE over lamps any day...but with a dimmer you wouldn't have to get rid of the lamp...just know that at any watt they suck humidity pretty bad and you may have to make a humid hide or mist a few times a day.

As far as the hide, she probably prefers the log hide, I suggest getting two identical hides, of any kind as long as they are tight fitting and secluded. Like I said earlier...they will trade security for safety.