I only want to see menu items specific to the ship types in a given fleet.
If I have a combat fleet, I do not need to load, unload, or colonize anything while I'm trying to blow stuff up. I don't need these menu items, and all they do is take up room. If my combat fleet does have transports or colonizers, however, I very much DO want to see those menu items. Context sensitive menus would only show orders that apply to the ships you're looking at. This would add value to the game in three ways. First, new players would be less confused when giving orders to a fleet - VERY important with the upcoming android platform launch. Second, giving orders would be faster and more accurate. Third, the reduced clutter would make Space appear even more professional.
Context sensitive menus already exist for planets vs fleets. My suggestion is to expand this to include colonizers and trade ships as well.
There could be a preferences option to turn off context sensitive menus. This way players have the option to still give orders to a fleet that are specific to ships that have not yet merged with the fleet.