RotatingAtom: To check IVs of your Pokemon, use the IV judge in Kiloude City. It's the purple-haired guy in the Pokemon Centre. If he mentions a stat and says 'It simply can't be beat!', it's 31. If he mentions the stat and says that it's bad, it's 0. If you want to check the exact IVs, you can ask someone with KeyBV/KeySAV to help you but you probably won't need to at all.
To find your TSV, find someone who can check your TSV (secret ID). PM
.com, he usually helps in this stuff. You just need to trade a Pokemon with your OT and ID. I'm not sure if you know how TSVs work this gen, it's different from past gens with secret IDs.
And one more tiny thing: you
don't ned a flawless Rotom, you can even start out with a 0IV one, replacing it with better offspring until you get your flawless one. Although having a flawless one off the bat will make it easier of course. Just so you know for future reference.