-Works best as a hit-and-run Pokemon due to the Special Attack drops from Leaf Storm.
I wouldn't word it as such, since you won't have time to switch too much given the fast paced nature of VGC. Instead say how Choice Specs Leaf Storm does hit a lot incredibly hard but one should be really wary about being locked into it given the special attack drops, and a good portion of common Pokemon resist grass attacks.
Give a brief mention to why this would be used over Rotom-W, especially on a rain team (beats a lot of problem pokemon for rain teams such as Gastrodon, doesn't add additional grass weaknesses to the team).
Little nitpick, in counters you said Rotom-H and Rotom-F resist both STABs but only Rotom-H does, F still takes a lot from a neutral Leaf Storm.
All in all it's a greatly underrated Pokemon, you've done a good job.