I'm keeping the heater away from the reloading bench... the heater is across the garage so there is no contact with anything else. There are other flammable items in the garage obviously, but I'm keeping it a safe distance from everything...
CO/CO2 - I did have to set it up to get some fresh air intake which seemed to make a difference... it was getting a little airless in there after a while.
Intresting thing though, I did bring out an extra CO detector I had in the house, it doesn't seem to register anything... I'll probably pick up another new CO detector at the store and mount it in the garage.