For F2P DEX Assassin (elf or halfling w/Dragonmark): 12+ APs Racial (Gtr DM), 41-42 APs Assassin (T5s + capstone), rest of APs into Acrobat (Shadow Dodge, T4s + Kip Up).
You were the one who argued
against Assassin's Kiss.
Have you since changed your mind?
If we're talking lootgen or Cannith-crafted weapons, kukris beat daggers for lvls 1-11 due to better crit specs. For named weapons,
Sky Pirate's Dagger and
Tiefling's Assassin Blade are definitely the best ML:4 options, IMO, and 3BC farming isn't hard - tedious, but not hard. [Maybe you'll get lucky and pull a
Kobold Uniform while you're at it.] If you like kukris,
Giant Stalker's Knives are easy to come by and good for ogres & trolls as well as giants; or a couple of
Blood Machetes, although
Sheridan's Wrack probably make more sense.
Then you get to lvl 12 and take Improved Crit + Knife Spec; you could stick with kukris, but like you said, there are far more named daggers and
Guardian of the Liturgy is great for ML:12.