Your DPS spamming Deadly Throw would still be abysmally low. You would just bring a ranged class.

Deadly Throw spam would be good on fights like the high king during whirl, gargoyles that are not quite low enough in hyjal, striders on vashj while waiting on naga spawns, supremus chase phase, or other similar fights where you cant stay in 100%. Atleast, it would beat doing absolutely nothing waiting to get back on target.

Two questions, with a HaT spec would you want to get daggers for CQC or would swords do more dps?
And some post say that in 25 mans the rogue never has a down time on CP, but HaT works only in group wide, so do the extra CP come from gear or are they getting more CP form critting raid members?

1) To get the most out of your poisonprocs, you'd want very fast daggers. To get most out of the occasional hemo you'll be throwing if your group isn't optimal, you'll want another weapon. Preferrably fist weapons, so CQC would still apply. Swords would be behind these two options.
2) The extra CP come from the crits within your 5-men group within the raid, which depends on both the gear they (including you) wear and the buffs they have. Obviously, in a 25-men raid there's a bigger chance to get all the good stuff in buffs than there is in a 10-men raid or a 5-men party.

What poisons would be best for that fast of attacks?

You would still be using wound poison and deadly poison on your weapons.