On the Illusion QD set, I'm not so sure about the moves you have listed. From what I remember, the best set was usually Bug Buzz, Psychic/Psyshock and Hydro Pump/Surf since this gives you your best overall coverage without having to resort to Focus Blast (perfect neutral coverage, bar Empoleon). Ice Beam is definitely usable, but its more of a secondary option since running it leaves you walled by a bunch of steel types.
The No Guard QD set, looks mostly good to me, but I might give a quick mention to Psychic STABs. While the powerful coverage moves are awesome and probably the better choice in general, these is also something to be said for simply running perfect neutral coverage using your STABs and a no miss Focus Blast.
Dragon Dance set looks good to me.
For the Choice Scarf set, I didn't use the Final Gambit variation too much myself, but from the limited experience I did have with it, I might suggest making the physical moves the primary slash. Slightly higher Atk and a much more powerful main STAB in Megahorm are really nice for something with limited attacking options. If the set was going to run more than 2 attacks on average than Special would be the superior option, but with just STABs, the superior power of physical is more advantageous. However, I would probably ask for more opinions on this, since I am not too sure about it. With that said, a pure Special Scarfer with No Guard and a bunch of powerful coverage moves was also a pretty good set in its own right.
Finally, in the checks and counters section, I would suggest giving mention to some more scarfers. Not a lot can reliably OHKO, especially if it gets a Quiver Dance in, but after rocks or LO damage or anything else, there are plenty of Pokemon that can finish it easily. Scarf Latios, Terrakion, Tornadus, Staraptor, etc. all can take it out more often than not. Of course, it should be noted that few of these can do it all the time.
<jas61292> I record everything
<nyttyn> prove it.
<nyttyn> WHAT WAS THE VERY FIRST THING I EVER SAID IN THIS CHANNEL.
<jas61292> [06/02/12 | 12:43] <NyttyN> Huh what deo you know shelll smash did get banned
<nyttyn> well congratulations jas your stalker nexus has reached an all time high.