20 Rogue, 5 Epic (Shadowdancer ED)
Starting Stats (28 point build) (if 32 point build, revel in a socially acceptable score of 14 Con):
DEX 20 (+6 Level-Ups, +3 Tome, +2 Drow Enh, +3 Rogue Enh, +8 Item, +3 Insight Item, +1 Exc Item, +6 Shadowdancer) = 52 (+2 Ship Buff because you will never die) = 54 (+ even more if you want to use twists on it - I would probably be more creative)
UMD, DD, Search, Spot, OL, Hide, MS, Balance, Jump, Tumble, Diplomacy. If you use a +2 Int tome add Bluff or something.
1 - TWF, [Shuriken Expertise free from Drow]
3 - Toughness
6 - Precision
9 - ITWF
12 - IC: Piercing
15 - GTWF
18 - Quickdraw
21 - Improved Sneak Attack
24 - IC: Slashing (solely for epic Midnight's Greetings)
Quickdraw and Shuriken Expertise from Drow give you a second form of attack. You will often (just over 50% of the time) fire multiple shurikens. Use spell-touched shurikens for their random effects to complement your huge Sneak Attack damage.
I would have loved to have squeezed in Rapid Shot for even more shuriken speed, but Point Blank Shot is a pre-req, and you just don't have 2 feats up your sleeve without gimping the melee aspect for far more than the bonus shuriken speed is worth.
Re: no Weapon Finesse. There are no weapons in the game that use Dex as Damage, but not Attack. So, for Weapon Finesse to be useful, you'd be giving up +26 damage per hit to use whatever it is. That would be a mistake that would ruin the good name of sub 14 Con Drow Rogues everywhere.
Assassin. Don't think twice. Your Assassinate DC will even work occasionally with some gearing.
Deadly Shadows. Despite Cheat Death's +2 Dex, it's just not worth 4d6 damage/hit.
Levelling (I am Australian. The extra 'L' stays.):
At level 4, equip some combination of Tiefling Master Assassin's Blades and Sky Pirate's Daggers from 3BC. These are pretty good and okay respectively, both being keen and using Dex as both to-hit and damage. The tiefling blade has wounding, +1 base crit-range and 1d6 poison damage while the dagger has a x3 crit multiplier instead of the regular x2
At level 14, equip Treason if you have one.
At level 16, equip 2 Envenomed Blades
At level 20, equip Epic Envenomed Blades.
For bosses and assassinations you want a pair of or single epic Midnight's Greetings - ideally slotted with Good DR Bypass.
Shadowdancer has an insta-kill ability based on dex - Executioner's Strike / Executioner's Shot. This should work well with either Shurikens or the eEBs.
Shiradi may also be fun to try for a while, but is a little gimp given this build has neither IPS or spells.
Ultimately, you want to twist in Whirling Wrists from Shiradi for 60% faster throwing speed.
The 'can't fail reflex save on a 1' thing also looks pimp since with your Dex and proper gearing your reflex save will be bonkers.
Sustained minimum 52 Dex for +26 damage on the few weapons you'll be using will keep you competitive with your STR based counterparts. You also have shurikens, a cool insta-death effect and panache. Lots of panache.
GET THE WEAPONS FIRST. At the least get 2 of the cove weapons, and 2 regular envenomed blades.
Your strength is awful. Lower carrying capacity and vulnerability to rays of enfeeblement and symbols of weakness are something you'll need to stay aware of. It's not a deal-breaker, since casters exist in this game and somehow manage to live. Just do what you can, carry a stack of lesser restore pots and do wear a +6 or higher Strength item once they're available.
DR breaking on bosses is your Achilles' Heel. Socket your weapons with good if you don't run Devil Assault much. Hope for an arti. Be unapologetic since you'll be doing very reasonable SA damage anyway.
Your other Achilles' Heel is 12 Con and d6 hit dice. Just gear properly and you'll be fine. That means GFL, Toughness, good Con item(s), and +45 HP Greensteel. Keep upping your Con items until you're comfortable or in +8 regular, +3 insightful, +1 exceptional.
Your third Achilles' Heel on this three footed monstrosity is enemies with immunity to SA. Undead (and Elementals?) smell. Do what you can. Dual finesse light maces of disruption or smiting might be optimal. *Shudder*