1..Yes we do.
2..Yes some people do use tire warmers on carpet.
But for me, t- warmers are more beneficial on asphalt.
3..I put it on the donut and then cook the sucker.
4..Get a warmer that can warm the front and rear at different settings.
Like the much more one.
Front at 60 degrees
Rear at 80 degrees
Hope this helps.