Well, I'd like my guy to have a little offense with his weapons, he is a pirate after all. And with arcane trickster, I lose no caster levels from that, and the only one I do lose is one from rogue, which only puts me down one spell slot(9th level, which is big, I know, but I can live with it.)

It's mostly just how I envision the character, I don't try to make fluff and mechanics completely together, but I don't put them seperate, I just try to optimize around fluff, which is easily possible. Hence, I am making a daring pirate guy with a quick wit and a few little magic abilities to trick his opponents, and he is not too bad with a Crossbow/Rapier. In mechanical terms, he is more like a Beguiler/Rogue(skillmonkey/slight SAer) Gish, but with near full caster progression. Sneak attack just fits well for a pirate/underhanded fighting character, and it's just a bonus that a beguiler has a ton of ways to make sure the target loses Dex-to-AC and to not get hit.

I'll be finishing off with Beguiler anyway, and leaving Beguiler only 1 or 2 levels behind Advanced Learning, so later on in my progression, I can hop back in and pick up Shadow Evocation once my caster level is high enough anyway, if I start feeling useless.

The only feats I am using for combat are Weapon Finesse for my rapier, and maybe Rapid Reload for my hand crossbow when I get multiple attacks(not anytime soon.) Other than that, just grabbing stuff to raise the DCs of my enchantment stuff.

On the Shadowcraft Mage build - it's good, I know, I get it. Something just urks me to use something I didn't build myself though. I'm sure someone has thought of this idea before and maybe used it, like most decent builds, but I just like creating my own characters and optimizing the way I envision them. I don't cripple them, but I'm not going to go look on around for a pre-made build that is optimized to, well, rape the game, to put it bluntly.