My 2 cents and sorry for my english:
We can have avatars but only for display medals, military rank or uniform and customizable face and maybe "diplomatic screen" for negotiate surrender, etc. Never for FPS combat. The work of a captain in battle is not combat in first line with a cutlass. But you can see the combat behind a line of "elite personal guard". The captain avatar is like a "ship flag", if enemy reach him, you have to negotiate diplomatic rendition.
For dress your captain you can choose various colors and items depending of the nation and some option according range (leutenant has fewer options than captain, etc).
If possible the captain can order tactical decisions like... direct control of a gun for marksman fire, destroy rigging and cut the ropes for end boarding, send another boarding party for reinforcements, open fire musketers before boarding or defend from enemy boarding, place crew resources where are more necesary, etc... But all without move from their battle station in "upper stern site I don't know the name in english" or the second commander if there's one.
The captain avatar is intouchable and immortal and limited movement in boardings but in normal combat of the ship you can move all decks or maybe direct control of a gun for range measure shot. In peace time you can move all ship.
I don't mean say to do to developers, only give them ideas. No fps combat smashing keys but a tactical combat simplified Total War stile.
I had the idea for add markers to show limits of gun elevation dependent of roll of the ship. Maybe show horizontal limits too, but I think that horizontal limit markers is not necessary and add too clutter in the screen.
