I remember how you could do stuff like this in FRED, the editor for Freespace, to create interesting ship events. This will be great for Starmade.
I would recommend also adding a /entity_rotate_speed command for admins to get things turning a little faster. I think this would be needed, because I imagine that the original /entity_rotate command in the OP would slowly turn entities at their maximum "normal" turning rate, so something to speed that up would be necessary when you just want something facing a certain way, and don't care if it looks like it is exceeding all known laws of physics to do it.
Maybe the rotate speed could be an additional three optional arguments for the /entity_rotate command? (E.g. /entity_rotate 90 30 180 10 10 10)