Here are my thoughts.
Sniper: Okay, this just won't work IMO. Look at all the Pokes who use learn Sniper: Kingdra, Octillery, and Dorapion. What sets them apart from Fire/Grass is that the above three have some sort of precise aiming method. Kingdra and Octillery have a very long and narrow snout, much like the barrel of a gun. Dorapion has razor sharp pincers. Fire/Grass has a bulky Bazooka. Not quite the same thing. Besides, this ability would hardly be of use in competitive battles. The above three are more sweeper-oriented than Fire/Grass is, and can thus make more use of it.
Battle Armour: Sure, this ability is fitting, and critical hits are annoying. Personally I don't think the point Aldaron made about SE critical hits will come into play that often. However, I still oppose Battle Armour for the simple reason that it's a very "meh" ability. People don't rely on critical hits in the first place to take a Pokemon down, so giving it an Ability to block critical hits, while nice and usefull at times, is just wasted potential IMO when something much more usefull could be used instead. Battle Armour wouldn't be the end of the world, but there's just much better stuff out there.
Rock Head: I'm pretty neutral on the "this does(n't) make sense" issue. Competitively speaking, I suppose this ability would be pretty good. Though apart from a purely physical set with Flare Blitz and Wood Hammer, I don't see this ability getting much use. Considering its Base Stats, this guy's primary purpose will serve as a physical wall of sorts, with a special attack or two thrown onto the main moveset. There's really no room for a physcial attack on the "standard" set. Leech Seed deals fine with Blissy. Ultimately, I feel this is somewhat like Battle Armour in that while it has its uses, and is by no means a bad ability, you won't get as much mileage out of it in the long run as you would for say:
Vital Spirit: Thank you chaos for the idea. This ability is perfect, and my number one advocate. Our guy definitely has "the look" to match this ability in my opinion. And then there's the competitive aspect to the CAP project, where Vital Spirit is plain fantastic. Guys, we NEED another way of handling Sleep inducers than ResTalking. Natural Cure doesn't cut it, and the only other way of dealing with it is something like Toxic Orb Breloom. No OU Poke has Insmonia (something I desperately advocated for Revenankh) or Vital Spirit. Please, we seriously need a better counter to sleep. I see so many people who are forced into a position to pick one of their six Pokes to incapacitate for the rest of the battle. If you're worried Vital Spirit may be too powerful for some reason, realize that Yanmega and Gengar (with Sludgebomb) can still give him quite a hurting, so it's not like those two sweepers are doomed against Fire/Grass. Now, in the way of healing: to be clear, this thing isn't getting a 50% recovery move (see bottom of my post), so some of you might be worried that even Rest isn't an option now. YOU STILL HAVE A SECOND ABILITY WHICH DOESN'T PREVENT YOU FROM USING REST. I may sound pedantic, but the number of people who didn't seem to realize this during Revenankh's creation is astounding. Plus, don't forget this thing will most likely get Leech Seed, and that's plenty recovery enough. What is this fettish with giving all our new defensive Pokes a 50% recovery move? Very few actually get one, and a Poke with 120HP and 105 Def, not to mention other great stats, can definitely live without one. So yea, choose Vital Spirit.
Flame Body: I like this ability, and could see it very well as a second ability. It makes sense aesthetically, and would work well competitively. I've rambled on for so long, so I'll keep this short by simply saying that this ability works well with its physical wall status.
Intimidate: Could be interesting, and definitely merits some discussion. Might be a little overpowered though, but this can be worked around if we limit Fire/Grass in other ways. Bottom line is I think we need to discuss this more.
Also:
NO 50% recovery, Rest + Subseed is too good as is. I'll do a write up later.
Agreed, well put that down on attacks it shouldn't later. Speaking of which, I got to post the final tally.
526 - 535: 16
536 - 545: 30