Your post was too boring and I couldn't read it. Hopefully the person who reported you managed to suffer through the whole thing. Here's what that poster had to say:
Let us help this person use the spreadsheet!
Originally Posted by Celebrim
I see. So this is something I really shouldn't be concerned with at the moment. Got the answers I was looking for.
Looking at your armory, even with Deathbringer's Will substituted for Grim Toll, you're nowhere near the about of arpen that you need to be in order to be gemming entirely for it. At 35/35 expertise, I would also entirely drop the expertise ring and boots for perhaps lower ilvl items with better itemization and use only the set legs for your expertise needs. If you have access to Sack of Wonder, you could swap out the legs and just drop the 4-piece set bonus because it's really not that good anyway. Being under the expertise cap generally allows for more dps that being over it (and especially, such as your case, being considerably over it). You're a full 73 expertise rating above where you want to be; you most likely have access to some lower ilvl items such as Dexterous Brightstone Ring which would be a considerable upgrade over Seal of Many Mouths in terms of your dps. I also see that you're gemming for agility and crit, both of which are big time no-no's when you're crit capped (which you are; I plugged in all your gear in the spreadsheet). I'm finding your EP value for agility at 1.4371 and crit at a measley .8586 (these are the values assuming DBW instead of Grim Toll). Crit in particular is something you'll never gem for as a rogue in ICC gear, as we find crit capping almost inevitable in heroic ICC gear anyway.
Generally, at lower ilvl gear sets or with gear sets that don't have arpen on almost all your pieces, you're going to find attack power gemming to come out ahead in red slots (or occasionally agility if a good ways under the crit cap) and something like AP+hit/haste or straight hit/haste will be best for your yellows. As someone above said, you'll likely need to be able to hit 900-1000 arpen for arpen gemming to take over all red and yellow gem slots as well.
Also, thanks Aldriana for the updated spreadsheet.