Something you already know, pick something and go with it. If you took out the 5 points from the Combat tree, I would say you were going for a SF/Premed build. Which is really suited more for PvP.
What are you looking for? Are you going to try and grind honor at 59, or are you grinding straight to 70?
Get rid of that dagger as soon as you can, it's not as good as you think. Imo, the 48 WSG dagger is better than that. 3 more top-end damage, better stats (11agi and 5stam) The thrash blade is a good weapon, just not a good OH weapon. It's meant to go in your main-hand, so it will proc more often off of you instant attacks.
http://www.worldofwarcraft.com/info/classes/rogue/talents.html?2252031050001222000000000000000000000000000001502200300000000000000
That is my build. I carry Gut Ripper MH and Scout Blade OH. The only spot I misappropriated points was between Imp KS and Imp Eviscerate. I'll be respeccing to Muti in about a week or two, and I can't wait to try it out.
You are trying to do everything, and that is going to make you inefficient. Pick something and go with it.