DRIZZLE AND SWIFT SWIM IS BANNEDDDDDDD
And also severely broken in doubles.
As for srsness, your team doesn't have a single resistance to Rock. While I doubt you're going to see +6 'Scarf Terrakion unless you're playing PO laddering, if you do, you're really ****ed. 100% ****ed. That alone is enough to say this team really does ****ing suck and won't succeed, but this isn't intended for VGC play, now is it? :P
You've got a nice bundle of resistances which make switching actually worth it if you predict properly, including key immunities to Ground, Fighting, and Water. Very good. Your team is really weak to Mach Punch spam though, so if you switch Gengar incorrectly, it'l probably be met with a move to OHKO it while it's team mate gets PAWNCH!'ed in the face, so Gengar with Psychic really doesn't cure your issue with Fighting types. Just like your Terra weakness, this is enough for you to scrap the team right here and now; if this were singles, anyways.
But your weakness to scarf'd fighting Pokemon is appaulingly bad. Sharpedo ain't going to save the day against Mach Punch, and Scarf'd CC will destroy the rest of your not-Gengar team.
If you miraculously are fighting a team without fighting types, however, this team definitely has room to succeed. You've got synergy, immunities, and the weather in your favor. If your Pokemon were of a higher quality, you'd certainly be taking even more victories...
So all things considered, it's a good team with a nasty and easily exploited weakness. Patch up that hole somehow though, and you've got a team of low tiers that are surprisingly deadly. Bang up job, bro. =)
... Did I mention that fighting weakness? ;_;