Level 17 Concept.. Pick holes please!

[Gandolfi Feesh]

Like most of you I've played my fair share of all basic classes, most of which have been based around the 6-13 bar height.
So when my friend agrees to DM a 17-20 campaign I jump at the chance to get the creative juices flowing. I would like to make it perfectly clear I'm not looking for anyone to turn round and tell me that a pure class seriously outguns me, I'm simply looking for ideas on how to round off an imaginative concept.

So far I've settled on the following:
Captain Corelli
Bard1/Barb1/Fighter4/Exotic Weapons Master2/Dread Pirate 9
(and yes, he owns a mandolin)

Noted Feats:
Combat Reflexes/Robilar's Gambit
Combat Expertise

Noted Weapon:
Vorpal Gyrspike

Class Abilities:
Barb - (CCh) Trade fast movement for Pounce ability
EWM - (CW) Flurry of Strikes (Emulates monk's FoB)
Pirate - (CAd) Rally the Crew (party buff - +5 att/dmg [item's included and it stacks with inspire courage], +15 temp HP and a +5 dodge bonus to AC... I like to buff the party.

Now with a near perfect BaB (-1 for Bard level) I'm able to dish out 4 attacks/round. Combine that with the Flurry of Strikes ability and I'm up to 5 and Haste or WRotF hits for 6.
Now combine that with the 2 free trip attempts I have from TWF bonus feat from Dread Pirate and the Gloves of the Balanced hands for a free ITWF.
The kicker is with a Dex of 20 I'm entitled to 5 a/o/o per round, for those of you unfamiliar with Robilar's Gambit it allows your foe a +4 att/dmg against you and in return you get an a/o/o "every time they swing at you"

In essence that allows me 11 vorpal attempts/round against a foe that full rounds me with 2 trip attempts for flavour.

AC:
10 base + 5 dex + 5 armour + 2 natural + 3 deflection + 5 combat expertise + 1 EWM + 1 Defending weapon property + 6 dodge (Dodge and Rally the Crew) = 38

Is there any way to improve my AC? My UMD is high enough for a shield wand but that's another round I'm not swinging my beautiful sword.

Also there are items to allow you to sneak attack/critical undead and constructs... If these were utilised would it become possible to vorpal these creatures???

Any hints or tips welcomed, thanks.

[olentu]

Er you can vorpal creatures not subject to critical hits without special shenanigans as I recall.

[GallóglachMaxim]

Vorpal has its own list of what it doesn't work on, to the best of my knowledge you can't get around that (you can't make an ooze or skeleton need a head, in order to cut it off).

[TroubleBrewing]

I'd avoid Vorpal. It's terrible.

Aside from that, looks like a lot of fun!

[Gandolfi Feesh]

I would say you are correct 90% of the time that it's terrible, however with a high AC and potentially 11 attacks per round that's statistically a vorpal threat every 2 rounds. Surely that has to count for something??

Say I end up taking the vorpal weapon, any suggestions on rounding my toon off against creatures that are immune to such things???
I should point out that we are going into hell, I'm pretty sure most demons and devils are susceptible to the big V

[Fouredged Sword]

Two feats, martial study and martial stance, will give you the blood in the water stance from ToB. Now you get a stacking +1 bonus everytime you crit. Also look into a Katori resin weapon (i think that is the spelling). It requires exotic weapon prof, but you have that, and it makes the crit multiplier X4.