Yes Vengence works very well with starbase.  Especially when it is under attack by strikecraft.

And Reverie does not work on starbases either.  IF it did it would be evil.

In my opinion the structer ships are fine just as they are. People need to remember they are the same as planet bombers and should be tissue paper. You need to treat them as such and make sure you have a safe gravity well before bringing them in, or you need to build a fleet around them with flak and repair to keep them alive. Either way those ships do what they are intended. Making them stronger would make it so they were impossible to kill with standard planet defenses and the computer and players alike would begin using them as attrition ships instead of clean and sweep ships. I wouldn't like the idea that a player could show up with say 6 of them and blow up a very expensive star base just becuase the SC protection in the gravity well would not be enough to deal with their armor and HP.