If you block shifted down with a quick shifter wouldn't that then require a slipper clutch?
Which my model doesn't have.
Hmm... interesting one. I guess you are referring to how when people usually block downshift, they keep the clutch in. With a quick shifter I would imagine it would be letting the clutch out on every change
A quickshifter won't do anything with the clutch. I'm not sure how they work on downshifts, but on upshifts it will kill the ignition for just long enough to take the load off the box and switch gears. Same as rolling off the throttle, just quicker.
A fundamental misunderstanding of the tech from me there :P
Besides this is usually discouraged (handbags at the ready) as any gear change can cause the gear teeth to misalign which is far more likely to happen the more gears you shift at once.
Citation needed! 
Probably, but I can't find anything official
I've experienced the issue and I remember my instructor telling me about it when I first started learning (he was riding a Divi 600 I believe, but I don't believe he was referring to his bike specifically). I imagine it is more of an issue on old and worn parts where tolerances aren't as great as when they left the factory. My 600 has a hissy fit when block changing but that's not surprising considerings its god-awful state :P
The theory behind it is due to the shifts never being perfect (granted this could be dealing with tolerances in the micrometre range) the teeth can be slightly out of alignment - on a single change this isn't something to be overly worried about as they will re-align themselves when engaged. By skipping through multiple gears, without releasing the clutch between, this misalignment is compounded to the point that the teeth won't mesh properly. As I said, this is the theory and may have been eradicated on newer bikes - its just not something I can find proper technical documentation on from a 10 min google search
In my head it makes sense, so I just avoid doing it
