Hey Milos nice looking rain team!
Ok looking at your team the lack of physical offense concerns me bit. This lets Chansey and Blissey wall pretty much your whole team. You did mention that Nasty Plot Thunderous-T beats Chansey and Blissey but i don't necassariliy agree on you there. After all to beat Blissey/Chansey Thunderous-T must already be a +2 predct Blissey to switch in and use Focus Blast twice without missing while also having Stealth Rock up. This scenario is very unlikely beacuse Blissey and Chansey would probally be in the field before Thunderous-T because they wall pretty much your whole team and even if they aren't any good player that uses them will switch them in as soon as they see your Thunderous-T come in. Vaporeon seems to me as the weakest link on the team beacause its spot for a bulky set up sweeper can me fufilled much better with Sub+CM Jirachi>Vaporeon This Jirachi set still provides your team with a bulky sweeper and one that can abuse rain with Thunder but also a pokemon that can beat Chansey/Blissey one on one due to him having 101 Hp Substitutes and Psyshock to effectivly hit Chansey and Blissey on their weaker defense. This set is also one of the greatest counters to Tornadus-T because he can set up in his face and resist Hurricane while also being able to beat Breloom by blocking Spore with Substitute and having Psyshock. He also helps against your Choice Scarf Thunderous-T weakness because Thunderous-T can be pretty annoying hitting 4 members of your team super effectivly with just Thunder and Hidden Power [Ice].
Another probelm i see looking at your team is its inability to take powerful Water-Type attacks from the opponents pokemon. Especially with Vaporeon gone Politoed is your only Water-Type resists amd with no defensive investment it will get murdered after a few Hydro Pumps from Rotom-W or a Starmie. I also agree with Jimbon in that Forretress slows down your team alot due to your teams offensive nature. So i suggest Specially Defensive Celebi>Forretress Celebi provides your team with an essential Water-Type resist while also being specially bulky this helps him to take on apposing rain teams and threaten with Leaf Storm. He is also a good supplier of Stealth Rock just like Forretress and Recover keeps him nice and healthy. He also helps your team greatly against Choice Band Terrakion and the previously mentioned Breloom who can tear your team apart otherwise Terrakion will be unable to really switch in because both of Celebi's stabs destroy it while Celebi is know as one of the best Breloom counters because it resists his stabs has Natural Cure to negate Spore upon switching and he can beat Breloom with stab Psychic.
good luck with the team i hope i helped!