I realize we've seen an admiral once wearing a gold uniform in Deep Space 9. However, are officers in the operations division limited to Lt. Commander, or do they have to switch to command to make Commander and above? Examples include Data, Geordi, Eddington, etc.
Yes they can!
The list of Starfleet Commanders shows that we do have some officers who are in Operations but have the rank of 'Commander'. Those mentioned on that list in the TNG era are:
- Commander Harkins, the head of the Pathfinder Project in Voyager
- Commander Kaplan, the chief engineer of the USS Intrepid in 2370
Others from pre-TNG era include:
- Commander Beach
- Commander Chekov
- Commander Kelby
- Commander Kyle
- Commander Scott
- Commander Tucker
- Commander Uhura
- Commander Yacobian
Going through that list I must confess that the majority of Commanders were in the Command or Sciences divisions and far fewer were in Operations, but officers in the Operations Division can definitely be promoted to Commander and remain in Operations.
In a word, yes.
There is no cannon that specifically states there is maximum rank based on job class.
I would imagine that an officer in any field is capable of reaching the upper ranks. A great example of this comes from ST:TOS and its movies.
Montgomery Scott held the rank of captain and he is an engineer. In fact, this character had command of a ship (USS Janolan).
Spock held the rank of captain as well and he was a science officer and 1st Officer of the USS Enterprise.
Some people believe that a Starfleet officer must change his/her designator specifically to "command" (red uniform); however, I do not believe this is true because when Worf was promoted to Lt. Commander and given a red uniform. He was a security officer and then became a Tactical Operations Officer.