I didn't make it!
As i'm a total STBC-newbie, i want to ask a question. In the standard missions you always have the Dauntless and later the Sovereign as your ship. Can you use another class of ships in the missions, and if yes, how?
Yes and No. No as in those are the only ships you get. Admiral Liu isn't going to offer you another class of starship. The "yes" bit is if you want to change some of the scripts you could call in a different ship instead of the Sovie, or Galaxy. Look on BCFiles for some ship replacements. Or you could change the scripts yourself. Look in the FAQ on how to do that.
Easy... find the file "galaxy.pyc" in your BC folder and replace/Rename it with for example "akira.pyc" (remember to make a backup" Like this: Galaxy.pyc --> Akira.pyc Akira.pyc --> Galayx.pyc (the easy way to make a backup) but remember that some missions more or less a specific kind of ship. for example the mission where you get Lt. Cmdr. Data aboard you will need a ship like the sov or at least a ship that has as strong shields.