Simmulated Dimmer Switch

I hav enow in use the Simulated Dimmer Switch to control my Panel Heater and it works but the simmulated switch needs enhancements.
First the device handler is categorised as lightning while it is a switch so the icon is wrong and the group is wrong. Does anybody know if it can be changed ?
And secondly I use the level 10, 30, 50, 70, 90 percent bullets to control the temperature of the device.
It would be nice if the levels were in full degrees Celsius. Is there anyone who could make such handler ?