I have two questions one is should the exterior plumbing stack vents be at least 3 feet above operable doors and windows.. In the bathroom a good location for a permanently installed ceiling heat lamp is where thanks new home bulider

I believe your right no the 3ft above windows and doors, there is a code for that ,but I'm not sure what that is, though I've heard it mentioned before,
As for the heat lamp we using install lights that come with the heat lamp built in. if not id probably put it just outside of the shower a few feet if you have room