Basically I bought a escort ship first when I advanced to level 11 but then decided since I had 40K money I'd buy a cruiser and try it out. Unfortunately it still retains the two tactical officer seats from the escort, and all of my powers disappeared.
To elaborate on powers, I mean all the utterly useful things like say, high yield torpedoes. I have the bridge officers for them, the officers are staffed in the officer seats, but the powers just aren't there.
Where I bought the cruiser: Earth spacedock.
What I did immediately after buying cruiser: Renamed it and customized it, and armed with with the good weaponry from my escort.