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I think it is a very interesting type combo and we don't have to make it over powered... just leave Draco meteor and Outrage out and give it meh stats without a good set up move, then it will have to chose between a powerful stab, set up, coverage, or support, and all are viable. Honestly I think that is exactly what this CAP is looking for, something that is unpredictable but not ridiculously strong.. I don't see the problem.
A Dragon with unlimited movepool isn't going to teach us much about sketch, just teach us how good dragon is as an offensive typing. Which we already know.
As much as I've been showing resistance to the idea of a Dragon type for this CAP, Grass/Ghost has too many problems:
Weaknesses: 2x Dark (A crucial weakness, as it means that CAP 2 will be weak to Pursuit. Not good)
2x Fire (Another common attack type. Heatran will force CAP 2 to run a Fighting type move to beat it, which will make Skarmory able to completely wall it.)
2x Ice (Common attacking type. Ouch)
2x Flying
2x Ghost (Yeah, CAP 2 can beat itself. Yay.)
2x Poison (not really relevant, but worth noting)
Neutral Bug (U-Turn)
Dragon (Scarf Lati@s will eat this thing for breakfast)
Steel
Psychic
Resistances Rock (resists SR)
Ground (EQ)
Water
Electric
Grass Immunities
Normal
Fighting (key switch in, although most Fighting types carry Payback)
As you can see, Grass/Ghost has not 1, not two, but 6 weaknesses, and 3 to common attacking types. This is too many for CAP 2 to fill a bulky attacking role effectively.
But that's not all. Let's check out the STAB offensive coverage of Grass/Ghost:
Super Effective (grass) Water
Ground
Rock Neutral (Grass) Normal
Psychic
Fighting
Electric
Dark
Ghost Not Very Effective(grass) Bug
Fire
Ice
Dragon
Steel
Poison
Flying
Grass
And Ghost:
Super Effective (ghost) Ghost
Psychic Neutral (ghost) Fire
Water
Grass
Dragon
Fighting
Ice
Rock
Ground
Poison
Electric
Flying
Bug Not very effective (ghost) Steel
Dark Immune (ghost) Normal
What should you take away from this? That Grass is a terrible offensive and defensive type, and that it being in the CAP does not help it at all.
Grass/Ghost have weak offensive moves to begin with; the only Ghost type move with greater than 85 power is Shadow Force, and that's a two turn move. Grass moves are more powerful, but come with terrible drawbacks: Frenzy Plant has a recoil turn, Solarbeam a charging turn outside of Sunny Day, Grass Knot requires a heavy target, Leaf Storm drops Special Attack, Power Whip has accuracy problems and low PP, and Petal Dance locks you into a move with terrible coverage for 2+ turns. Leaf Blade and Wood Hammer are both viable, but that's about it.
So, I encourage everyone to vote Poison/Dragon.There are in fact ways to compensate for the Dragon type (like bad Sp.A to discourage the use of Draco Meteor). We don't have to give it Outrage. We don't have to give it Fire Blast and Earthquake from TM.