If you could place the heating pad on the underside of the wire, you would eliminate the hot wire issue. I'd also lose the towel beneath the "mama" due to the poop that will be deposited there. Better to place wood shavings there to "lose" the poops into, rather than the cloth that will hold onto every deposit and the young ones will have to bed down on repeated poops stuck to the towel. With the wood shavings you can clean under the brooder in about 2 seconds, whereas the towel will present more of a problem.
I'd also keep that back end open a little to allow for good air flow and escape if the chicks are crowding up too much in the back. A hen doesn't have a back end that closes and chicks can come and go from all sides, but since that isn't possible with this brooder model, we can at least create more access by opening up both ends of the "mama".