Allan W
The quality of paint and paint job on your grill will determine how long it will take, but yes, it's going to rust eventually. The paint, even though it's make for high heat, will succumb to heat and then rain or humidity. To minimize the rust, you should invest in some type of nylon or waterproof grill cover to protect your investment. As far as the cement goes, I don't understand this part of the question. Are you talking about placing some protection below the grill? If so, no. The concrete will not need any type of covering and any dirt or ash will clean up easily. Your propane tank will be ok if you keep it out of direct sunlight on really hot days. Even if you forget, I've never had any problems before here in the South and haven't known anyone else who's had one blow. In the winter you shouldn't have to worry about it at all.