I somewhat forgot about the decision to go with the crutching cap of 8 debuffs in their recent decisions. So yes, a dedicated marks man would probably be out of the question. After the change, back into 16 slots, you are fine though.
Being said though, the 2 points don't really have anywhere else that much better to go. Arc shot shares CD with aimed, so that's not viable. You never use serpent sting at cap (Ever). And imp scorp shot is quite usless too. That leaves imp conc shot, but most mobs don't need to randomly be stunned or dazed in raids. So really, leaving those extra 2 in imp mark is still a viable choice, being conc your only 2nd.
As for 9% hit to surpass the 8.6% on level 63 mobs (bosses) for tranq, I've heard different things about it. Some claim it requires spell hit cap of 16-17%, others say 8% is fine, and in honesty I skipped over it in my head and just went for the 8% cause I was lazy. I've played a few times with 8% hit, and never missed tranqs, or many at all any shots in general (from other servers, so can be very misleading to true calculations blizz wanted).
I've also made a
loosely verified pre-raid list from allahkazham's wayback page of pre 1.3 patch data. Not 100% absolutely sure about each item, but somewhat in the right direction if anyone is struggling to get a footing on some cap gear.
List is hereFunny seeing how little to no trinkets were really open to players that early. Anywise, covers the 9% hit, has some notes about switching items if lucky, but will very much so change when 1.3 patch and later come out (a lot of goodies from DM for hunters).
Edit**
Completely forgot about the 2p bonus from devil gear, for that sexy +2h. Means you'll have 9% selfbuffed from gear (although stat wise for dmg you might feel weak gimping for hit), so you could either go back into SF for +x to drop some +1-2h gear for dmg. Not a whole lot out there yet, so perhaps just going straight up 20/31/0, skipping the wolf party buff, and going cat deeps till you get 16 slots for imp mark, might be the better raid dps option. Don't care to go theory crafting when you can't even test your math.