If you have weakness policy, why do you have Dragon Dance over Agility? A Dragonite at +2 due to weakness Policy is already very threatening, and the only thing it lacks will be made up for with Agility. Also, run Adamant > Jolly for more damage.
I would suggest Earthquake > E-Speed and Fire Punch, just to hit bulky steel types (Heatran mostly)
I really don't think a ghost physical wall in OU is a good idea, mainly due to the fact that Knock Off and aegislash are running wild.
I suggest a physical Gliscor as a replacement. Not only does Toxic Heal Gliscor not mind the Knock Off after it gets poisoned, but your team really walls water and ice type moves, so it's weaknesses aren't even a problem.
I really do't see the special wall in this, so I suggest giving Venusaur the job of special wall, and just making this thing a full out sweeper. That way, you're abusing Snorlax's full potential.
Why not make this a bulky sweeper? Heatran really does not have the speed to run Timid, unless you're running a scarfed set.
If you change the EV's a bit, like say change the Speed EV's to HP, you will find yourself tanking hits much better and especially countering Talonflame.
Swampert is good, just run Ice Punch over Stone Edge for 4x effectiveness over dragons. Rindo Berry doesn't match though, so run Leftovers.
Venusaur is good, however, I really dont' like using Leech Seed. Most of the time it never gets used. Either run Knock Off or Roar as a coverage move to really help out your team. I recommend Knock Off since Swampert gets Roar.