Special Forces officers (18As) generally command an ODA (operational detachment alpha - the A-teams) for 18 to 38 months before they move on.
SF officers are Captains, so they already have experience in their basic branch. They go through 90% of the same pipeline enlisted potential SF soldiers do.
Where you go when you move on will depend .. you could be in a staff position (no one is immune to staff jobs) or you could end up as a company commander of a special unit, then, maybe a few more years as a battalion commander (or more staff time). SF officer careers vary, from staff positions, foreign liaison officers, specialty company officers, to training officers or, if they want, end up back in big Army working with conventional branches.
One cannot say they will never see combat past the rank of Captain, or go on real-world missions because it is simply not true. It is, however, less likely as one progresses in rank. You become more of a planner and policy maker/enforcer, be it by your command or someone else's.
If one wants to spend a vast majority of his career playing in the dirt .. becoming an officer is not for him.
Rotating members out of units is not a bad thing - it helps to pass on learned leadership and training to other units, therefore, helping to make a better, stronger Army.