Just a note you seem to be too concerned about sticking to roles. Every team doesn't have to have those things.
Darmanitan also wants U-Turn over Earthquake, this helps it scout and plus EQ has very poor coverage compared with its other moves and wont hit anything they hit.
Rain Dance also seems silly on Roserade, all it does it make Darmanitan suck really (weakening its main STAB move) and weaken Sceptiles HP Fire. Use Sludge Bomb or HP Fire over it. I prefer Sludge Bomb in UU though. Kingdra can pretty much sweep on its own regardless in UU so doesnt need rain.
You are actually Sub Plot Mismagius weak, it can set up on some of your team and when its behind a Sub it really nails you with SR up. Id try and fit in a counter or check over Sceptile tbh who isnt seeming to do much. Something like Escavlier would work quite nicely, especially with hazards up. This also helps you take CB Outrages from things like Flygon which your team currently cannot.
Escavlier @ Choice Band
248 HP / 252 Atk / 4 SpD / 4 Spe
- Iron Head
- Return / Double Edge
Lastly, Chansey wants Seismic Toss over Heal Bell. You dont need Heal Bell when you can just make Dusclops Rest Talk and you have Natural Cure mons all of which can easily take your status.