Soolin is a hired gun & one would think that to do her job she would have trained herself to size up an opponent in a glance paying attention to things like body language & where & what type of guns they have. However, Soolin didn't seem to notice that the guns of two alleged guards were different from the guns of the typical Zarok security?

Avon calls Servalan "Servalan" in front of her guards. Does this mean that she will kill them for knowing her secret?

Summary nits: I believe it is an old friend of Vila's, not Avon.
They are stealing the gold from the planet Zarok, not the Federation. It's only at the end that the Federation takes over Zarok.

If Avon did suspect that Servalan was behind this, why not set a bomb with the gold, and/or wait for her ship to leave the planet & destroy it?

The Space Princess has tin & white plastic canteen trays stuck to the walls, as well as a CCTV dome camera fitting. Boots & Stockport had one of these until the late 1990s

Anyone know what music is played on board the Space Princess?

This is a great episode, the mix of comedy and drama is just right without ever going too far into the realms of silliness and the late Roy Kinnear gave a finely judged performance that although usually amusing can equally be quite nasty, the bit where he shoots the doctor being quite chilling. Keillor definitely claims to be a friend of Avon and doesn't even meet Vila until he boards Scorpio. As for the music from the Space Princess it was almost certainly written specially for the episode by Dudley Simpson. Whether you loved it or hated it it was certainly memorable - bits of it stuck in my mind from the time of the original showing for years.

Have you tried Mental Floss to remove those bits?