I know there are Flight Safety instructors who have never flown the type they teach. They generally hire people who have experience flying in the corporate or airline world and I'm sure they would give a higher priority to hiring someone who has flown the type that they are hiring for, but that doesn't seem to be something that they actually require. Most of the instructors I've talked to at various Flight Safeties have said they got into it to be home everyday like UNDGUY said. They make pretty descent money fairly quickly with descent benefits, though I've heard they recently stopped giving newhires the same retirement benefits as those who have been working there a while.
The schedules they have are not 9 to 5 since the sims usually run about 20 hours a day, but they are home at some point every day or night and they typically have work schedules more similar to airlines in that they don't just work Monday to Friday and they tend to have more time off than most jobs that you don't have to travel for. I've also seen many instructors who do both ground and sim training. I think most start out teaching the ground classes and then blend into sim training also, but to totally segregate it would restrict flexibility for training when things get really busy. This is just what I have seen training at two different Flight Safeties and I can't really say that this is the case in all their facilities or airplane programs. I can say that most of the guys I talk to there like their job and that Flight Safety has always done a great job training me.