Alright it seems that you have to do a lot of switching in the beginning of the game due to you have three pokemon that have to set up either Toxic Spikes, Spikes, and Stealth Rocks this way when switching your easily allowing your opponent to set up on you then sweep your entire team.
Like Dragon Dance gyrados will be able to get 1-2 Dragon Dances then Roserade will die if it has ice fang or even by a earthquake.
Then Stone edge on Skarm will OHKO it after 2 Dragon Dances.
Waterfall will OHKO heatran.
Waterfall will OHKO Gengar, and Tyranitar.
The it out speeds manaphy, and a stone edge, and it's gone.
I would suggest Stone edge over SR on tyranitar, but don't worry you will regain SR. This way Gyrados won't be a problem when it's switching in or any flying/Dragon type. Then remove Spikes on Skarmory, and add Stealth rocks since theirs too mainly flying or levitaters on a team. Also Stealth Rocks shuffle with WhirlWind is more accurate it hits all pokes.
- Good team in all.