I really like your team and I an see it working quite well. There are some isues though:
I never thought that I will ever say this in Platinum, but once Tyranitar is down, Celebi will wall your entire team. Can be fixed easily though: Replace Psychic with Flash Cannon on Jirachi. This makes it easier for Jirachi to set up and also means Tyranitar has a much harder time against it. This works especially well together with Gyarados, because with Taunt, he can usually simply set up on Swampert.
Speaking of Swampert, it might be beneficial for most of your team members to have him out of the way early in the game. Which is why I suggest squeezing Celebi or Roserade in there somewhere. "Tinkerbell" might suit the semi-offencive style of your team:
Celebi @ Life Orb
Modest
232 HP, 244 SpA, 32 Spe
- Leaf Storm
- HP [Fire]
- Thunder Wave
- Recover
Hope I helped. Sry for not going into detail more, but I's gotta go to Uni now.
How exactly are you bluffing a choice item? Spamming bp is going to get you trapped by zone. Anything that comes in expecting u turn is resisted by superpower, not to mention iron plate is only boosting one move, which is irrelevant once you get a sd in. So..why not try shed shell on scizor to avoid being trapped by zone if you don't care about power? And this team has an absolutely atrocious gyarados weakness. I don't normally recommend this, but put hp electric on pert on that last slot and everything should be fine.
If you want to be less dependent on scizor revenge checking salamence, you could move swampert to the lead position and put toxic over u-turn on gliscor. This means salamence can't switch in and DD anywhere, as you can hit it with toxic and then predict around it's switches until SR/Life Orb/Toxic/SS damage brings it to death or low enough to where scizor can finish with BP. I've done this several times and only lost about 1 poke each time. You could then put shed shell over iron plate if you wanted to.
Also, if you're running wish on Jirachi, there's a set I saw on an RMT a little while ago from a world cup team that I really liked. It's more of a tank really but it can help heal gyarados/tyranitar more easily while still setting up on many things. Anyways, this is the set.
Jirachi @ Leftovers
Serene Grace
252 HP / 252 Def / 4 Spe
Bold (+Def -Atk)
- Calm Mind
- Wish
- Psychic
- Thunderbolt
You could opt for flash cannon over one of the attacks to help out with Ttar and latias and not being walled by celebi as said above. This set beats Blissey outright thanks to flamethrower being very weak after a couple CMs and access to wish.
Oh, I didn't see the Jolly Gliscor. My bad.
I'd also stick with Substitute since you can play mindgames with the opponent and prevent being Tricked on. Also makes beating Seisimic Toss Blissey easier. I'd almost recommend ScarfTar though if you think Infernape will be that much of a pain and you want to keep Swampert, but of course locking yourself onto an attack sucks.
If you're going to feign band on Scizor, you *may* want to consider U-turn over Roost. Due to the popularity of Scizor, every team has some sort of counter/checks to it, so due to that Roost doesn't really net you any great benefit since you either set up or you don't. Swampert is the only opponent I can think of where Roost may net you more SD than you would've otherwise, and even then it's fairly easy for Scizor to deal with with U-turn as it lacks recovery. I have a SD/BP/Superpower/U-turn Scizor on my team and it sweeps just fine since I can still set up multiple SD when they switch in something like Forretress, Bronzong or even Gliscor.
Alright, I got your PM, so here goes.
To be honest, I can't really find any big weaknesses on this team since you appear to cover them all pretty well. My main concern, however, is that special sweepers such as Life Orb Latias and Gengar are able to weaken your team sufficiently as Scizor's current EV spread is ineffective in handling both of those threats. Instead, since you are running Swords Dance anyways, I'd like you to try the following EV spread: 248 HP / 84 Atk / 176 SpD. By running this EV spread, Scizor will have a little bit more insurance against those special attackers, meaning that you can even set up Swords Dance on them whereas you could not before as you risked a 2HKO.
You may also want to run Life Orb on Latias instead of Leftovers as you stated, as with a combination of decent durability and Recover, the extra power will, in the long run, help you out more instead of the slightly better durability that Latias does not need.
On Jirachi, since you are not running Substitute, you could always drop down your HP to 401, given by 240 HP EVs, which will allow you to survive 5 consecutive Seismic Tosses from Blissey after Leftovers recovery, although that's slightly redundant due to Wish.
Heatran could run Explosion instead of Hidden Power Grass since Latias switches into Swampert with impunity.
Anyways, what I'd like you to do is perhaps share your experiences with this team and let me know if you have had any specific problems you would like some help with. As I said, there aren't any real problems on paper, so in order to provide the best suggestions possible, I'd like for you to provide said information if you can. Other than that, your revised team seems sound. Good luck!
I have a problem with the Heatran lead, Jirachi is going to trick you regardless of you using Earth Power. Giving him Fire Blast/Flamethrower will make him a more effective revenge killer later on. Or scrap the lead entirely since you don't need to counter Metagross leads as he has little power against the rest of your team. Yu may want the lead to do something like set up Toxic Spikes so you can stall with Latias, Gliscor, Jirachi or Scizor (looks like it could be a semi-stall team). I hate recommending the now common Roserade but it may just be good on your team.