Tri-Attack does have competitive value I would say, serving as a VERY neutral attack that isn't resisted by too many pokemon that are already hit neutral by Thunderbolt or Dragon Pulse. Allowed.
Vacuum Wave should also be allowed. Surf does more to those targets anyways, and I wouldn't have planned Stratagem to be a check at all to this pokemon (I cannot wait for the name poll; calling this CAP8 is so annoying).
Explosion and Self-Desitruct definitely unallowed. It completely gets rid of Blissey and Snorlax as potential counters, and it is fast enough to cripple even several pokemon who resist it. This is a no go for me.
Weather Ball could easily be allowed. In sandstream, it is a special rock move. Thunderbolt already hits many flying types hard, and the only thing Rock gives coverage on is Syclant and Salamence really. It is already likely getting a Fire move, so sunny day isn't going to be a big deal, likewise with rain, and Hail means an Ice move that would only hit Salamence and Flygon harder, whom I believe Dragon Pulse hits just as hard or even harder factoring in STAB?
More opinions to come.
EDIT:
I actually do not like Extrasensory or a psychic move all that much. It prevents bulky fighting types from coming in, especially Revenankh, whom I feel would be a decent enough counter after playtesting. However, I won't vote either way on a Psychic move, as fightings wouldn't suffice as counters as much as Tyranitar or Blissey would.
Spacial Rend should be Unallowed. Sure this pokemon is bulky and meant to take hits longer, so Dragon Pulse fits this rather nicely, but that critical hit ratio absolutely kills it for me here. I would rather go up against Draco Meteor than Spacial Rend. (Perhaps some people will criticize me for this, but in my experience moves with critical hit rates are rather dangerous)
EDIT AGAIN:
Pending:
Explosion
Selfdestruct
Mist Ball
I have stated my opinions on the first to moves, but I believe Mist Ball should be Unallowed. A 50% chance to increase the ability to take special hits is crazy for me, and no way would I want that.
Controversial:
Fire Blast
Flamethrower
Lava Plume
Flamethrower for allowed, the others for not allowed. I just feel that Fire Blast and Lava Plume with their Power/burn rate respectively would make CAP8 too powerful, whilst flamethrower is relatively low in power to those, and allows it to combat Jirachi and Scizor more often. This thing will be THE Scizor counter, but I don't want it to threaten other pokemon too much, especially Celebi who doesn't Like Flamethrower as it is.
Hydro Pump
Surf
Surf for allowed. Hydro Pump for Unallowed. Surf won't be too threatening to Tyranitar, who may be one of the best counters to this as far as I can see, but Hydro Pump is way too much for, providing extremely powerful coverage with a Dragon Move. If anything, I want Water/Fire moves to be mutually exclusive on this pokemon in the same sense arghonaut can't have Recover and iirc Bulk Up.
Focus Punch
Super Power
Earthquake
Focus Blast
All unallowed. Focus Punch and Super Power are no-goes for me on a count of Blissey, Snorlax, and Tyranitar. Earthquake and Focus Blast for essentially the same thing, though Earthquake more for the fact it might hit Steels investing a bit in Special defense to beat this thing. I don't want this thing to be able to beat all of its potential counters x____x
Unallowed:
Aura Sphere
Earth Power
Close Combat
Hammer Arm
Cross Chop
Grass Knot
Spacial Rend - Didn't see this earlier; good. :D