| Calious |
Personally I think that the weapon is cool and enjoyable. It really depends on what exactly you need from your weapon. For a gunslinger this is a bit more of a varied stealth weapon. if you have a weapon already that you can smuggle into most scenario's I wouldn't really recommend it, on the otherhand if you don't this isn't the worse choice available with some long range ability and the ability to poison your bullets (which will hardly be wasted given the whole hitting touch AC). I personally think it's better then the bladed scarf especially in terms of flexibility in situations you can use it in.
As for telling you about the sword cane pistol is, it's an abomination of a combination weapon although and can be made out of anything you can with the coat pistol. If you want you can make a solid argument that the weapon is actually a 1d4/1d3/1d4 as you could bludgeon someone with the cane as well (although it'd be pointless given the fact that the blade deals 1d4). As for how you'd fire it it'd be up to you to describe it flavor wise, the blade can pop out or have the gun be part of the handle with the trigger somewhere on the grip.
As for Sword Cane vs Sword Cane Pistol depends on if you are willing to spend the feat to be able to get it and take the minor damage reduction.
Sorry if this is really really late.