See this thread:
Rogue DPS Spreadsheet
Read the first post. Read some more posts. Read the last few pages.
Download this spreadsheet:
http://www.savefile.com/files/819845
Read the intro.
Fill out your talent.
Fill out your gear.
You can now see your theoretical dps. Both buffed and unbuffed.
Play with talents and gear.
Check the "next_stat" tab.
There you can see the increase of each stat to your overall dps.
You are forgetting many things in your calculation.
Talents increase crit damage and crit chance.
There's differences between swords, daggers, fists, maces.
There's differences between buffed and unbuffed dps.
Basically, the better gear you have, and the more buffs you have, atp becomes less valuable, and crit becomes more valuable.
Btw, the best thing to increase your dps, is probably to look at +hit.