What point to the Davy Jones scenario,
The chance to meet a character from the "Pirates of the Caribbean" films? The chance to try your luck at taking on the
Flying Dutchman? But if the scenario does not interest you, you are free to ignore it - it's a sidequest, not critical to any of the storylines. (Unless you're referring to Davy Jones' part in the "Hoist The Colours" storyline, which is heavily based on the "Pirates of the Caribbean" films and there'd be a lot more complaints if Davy Jones
didn't show up.
)
the french frigate Speightown scenario if I can't keep it,
That's part of the "Tales of a Sea Hawk" storyline, and at this point you're working for Governor Silehard. His agent has set up the capture of the ship. Your job is simply to deliver it.
That is the same sidequest which ends with you facing Davy Jones. If you don't want to play it, refuse the job when you first talk to Governor Shaw.
having items of value for females if they cannot be given and some appreciation garnered?
One of the storylines does indeed use some of those items, depending on how you play it.
What about the Port Royal thugs who cannot be killed in order to deliver the sealed chest item?
Part of the "Tales of a Sea Hawk" storyline, this introduces you to the cursed pirates who are immortal. You will subsequently learn more about the curse in general and the chest in particular.
Why are my bodyguard cohorts in boarding always getting trapped in the lavatory by an opponent when the space is too small for swordplay and why are all three in the lav when the one opponent steps into the doorway and starts whacking away?(
The only place I can think of where this happens is one of the smaller cabins at the end of a boarding battle. Space is small, the reason being, it's a small cabin. You're duelling the enemy captain and one of your associates is duelling one of his associates. But it's a bit unfair to say that your officers are always getting trapped in there because in order to get to that cabin, you'll have been through at least two decks where there was rather more sword-swinging room.