I certainly think there could be more powers for Engineering and Tactical,
The shared cooldowns for Engineering and Tactical and Tactical's weapon load-out dependent options overall limit build options.
As a Science Vessel Captain, I can't have enough Ensign slots, they are all good and you can avoid a lot of cooldown sharing. Tactical and Engineering really don't want more than 2 Ensigns of their class.
Agreed entirely. As a cruiser captain I usually end up just running 2 copies of Engi team 1, since my 2 Emergency Power powers are higher up (EPTWIII and EPTSII), but even that means one of them almost never gets used since I also have Tac Team I.
Here is another ability that could greatly improve Cruisers:
The ability would redirect an enemy sensors to you, and make their previous target un-targetable for 10 seconds. It would have a base cooldown of 30 seconds,and specced into a cooldown of 15 Seconds.
Far too much uptime. The standard 45 base, 30 specced would be good with a 10s break. Otherwise, it's a really good idea for an engineering power since Cruisers are supposed to be "tanks" but there's no increased aggro powers like in other MMOs.