Does Telling Blow really help that much? A dagger has a 19-20 crit range, and if you're not SA'ing, chances are you're trying to SA next round and won't be able to hurt them very much anyways...
Getting Brilliant Energy Weapons, when you can afford it, means you really don't need to go fighter for the bab, though I can see going 4 levels in and getting melee weapon mastery.. which doesn't apply to thrown daggers, which is bad..
Ranger/Rogue actually makes sense, in an odd way.. almost as many skill points, full BAB, and 2 free feats if you go 2 levels in.. But I dunno.
Hrm, so much to think about. Personally, I would do something like Rogue/Swashbuckler/Invisible Blade (Daring Outlaw), except the Swashbuckler levels don't give Hide/Move Silently as class skills, which could be annoying..