Hey
This is a well built team, I especially like seeing a Poison Heal Breloom for the first time since BW2 release. Besides your threat list, I saw Standard LO Mamoswine and Double Dance Terrakion as major threats as nothing on your team likes taking hits from either of them and they can both defeat you in a pinch if you don't handle them well.
First off I think with Rapid Spin support, Tornadus-T would much rather use a
Life Orb > Choice Specs. Once you have worn yourself down with Life Orb you can simply switch out and recover the health back and the ability to switch moves is golden on Tornadus. Latias's EV spread looks a bit funny for a CM user, so I think switching EV's to
252HP / 4Def / 252Spe would work a little better in aid of setting up and still maintaining a blazing speed stat.
Next, I saw that all of your weaknesses could be patched up be
replacing your Forretress for a Life Orb Starmie. Starmie can beat all of your threats with a monstrously powerful Hydro Pump in rain, Reuniclus is still 2HKO'd at +1 and opposing Starmie are forced into a speed tie scenario. Gyarados is beaten by TBolt and jirachi doesn't like taking Hydro Pump at all. Forretress should go as with the abundance of Rapid Spin and your lack of a spinblocker, you will often find your hard earned hazards getting wiped off a bit easily and Starmie still provides the rapid spin support that your team wants. Also of note is that Reuniclus can't recover stall you as even with Leftovers Hydro Pump will negate all possible recovery at +1
GL with the team, Starmie set below