Nice guide, I wanna add (at least for my experience) that the assassination spec is quite simply to learn and has a nice output damage overall, but I won't choose it as a permanent end-game spec. Almost every top guild go in raid with combat rogues, and I see why, I was close to be BiS gear, 6300+ gs, BiS weapons, 25-30% haste, tried both hekumi and Taiaj trinket but couldn't pass 15k around on static bosses like saurfang/festergut/rotface. I mean for pug runs its pretty awesome and you probably will shine on the top of the dps meter, (maybe you will have some trouble surpassing smourne warrior) but if you want to maximize the damage done and be a dps god you should definitely go combat.
Also if i didn't miss it while reading, no one mentioned that Taiaj is bugged, and should proc with offhands/poisons, which doesn't happen. Correct me if i'm wrong.
Now i switched to combat and I see a huge difference, and I have way less gear. Not saying "go combat or you will suck" but keep in mind that this spec has some limitations, despite you good gemming, gearing and using a perfect talent build and a perfect rotation (my envenom uptime was close to 100%, by using 3cp envenom rather than waiting everytime for 4+ CP, which causes often to be without envenom buff for 3-4 seconds and that is a huge dps loss). so it depends on you about how you want to play, and what your guild is looking for.
I personally changed to combat only because of my guild, but if I would chose I would stay assasination all the time, no doubt :)