Disagree with your points on Infernape and Blissey. There's a reason Choice Band is the go-to item on Scizor; U-turn is great for choice users. (Which reminds me, I need to try a scarf/banded set on Hydreigon sometime, due to its access to U-turn, Outrage, Crunch, Superpower, etc.) Flamethrower Blissey is good for countering common switch-ins like Scizor and Aegislash, the former of which can be OHKO'd due to the 4x weakness and the latter of which will likely be expecting setup bait.
Now, back to the rest of the team.
Infernape looks good, though usually a lead infernape is setting rocks/taunting/etc. You have shock factor, and you should be able to take out common leads.
I would run Leech Seed over Spikes on Ferrothorn. It's more common, but there's a good reason why. It steals a little momentum and helps counter setup sweepers by ensuring their HP will be worn down over time, thereby forcing a switch. Gyro Ball might be slightly better coverage, but it's really preference.
Sharpedo also looks fine except for the aforementioned Ice Beam. Sharpedo can run a special set, but mixed sweepers are questionable, and your Adamant nature does you no favors in that regard.
You lack a cleric; sleep will essentially leave you with 5 pokemon if they use it on something other than Blissey or Altaria. Burns also cripple the majority of your team due to a lack of special attackers (Blissey doesn't count) and/or status absorbers. Indirect damage helps with that, going back to the aforementioned Leech Seed on Ferrothorn.
I would recommend grabbing something with phazing, too.