Gyarados, Jellicent and Keldeo all resist Bug Buzz.
As for BulkyVolc, base 100 Speed is actually a letdown since faster Scarfers are so common - whenever Volcarona shows its face, the opponent is going to send in Scarf Terrakion and hit it with Stone Edge.
This is irrelevant to the bulky set. Both are outsped by Scarf Terrakion.
Also, just because Gyarados, Keldeo, and Jellicent resist Buzz doesn't mean Giga Drain is the best third option. You pick your poison. You pick Giga, you lose to Heatran, and Dragonite and you don't do enough to Tentacruel. If you use HP Ground you hit Heatran, Tentacruel, Terrakion, but lose to Gyarados and Dragonite. You get the picture... Generally for most teams though Heatran and Tentacruel as walls are more of a dick than the other dudes.
I'm sorry to say this, but I don't think this is up to the quality that Volcarona needs. While it's true that Volcarona is in need of a revamp, i'm afraid that I find that your writing just isn't up to par, especially when you take into account how important Volcarona is and the original analysis's high quality. While we appreciate and encourage the contributions of newer writers, we also encourage newer writers to start with easier analyses rather than jumping in with both feet on a more important and more challenging Pokemon. If I may offer some constructive criticism; The writing is decent, but your sentences are short and fragmented, and the overall flow is stiff. I would suggest against structuring your analysis around stringing bullet points together and focus on writing a flowing analysis that isn't quite so flat.
I hope this doesn't dissuade you from writing any more analyses in the future, I really hope that we can meet again under different circumstances.
I'll do it, Breloom and Landorus-T are done and I love me some firemoth.
Also I'd like to note something. The Quality Control stage is for skeletons only. Don't write an analysis and post it during QC stage, as it makes it harder for QC to piece together the relevant parts of the analysis and judge it effectively.