Sorry for the very late reply, but-

Why I'm not the killer
No real motivation for actually killing anyone. It's a competitive event yes, but everyone here is cool and people shouldn't pay with their lives for potentially being a threat to someone's chances of winning. Also, I'm very squeamish around blood, gore, and corpses and all that, so there's that, too.

Favourite Colour
Blue and Purple. Not sure why this is here, but there ya go. :v

Any ideas they have to deal with a killer who at any time could just drug us all and commit scallywanglery without anyone noticing.
I'd personally suggest wearing subtle body armour (IE. Knife-proof vests) underneath our regular clothes so that knives and things don't have an effect. Also, keep as much of an eye out for suspicious people and anyone tampering with say, food, drink or ventilation as possible.

Strategy for fighting AIR
His front end is quite narrow and he's quite a bit slower than I am as well from what I recall, so what I'll do is focus predominantly on attacking the vulnerable sides/front corners of AIR, avoiding taking it head-on to minimise the risk of getting caught on the Flipper. Keep underneath as much as possible, flip him around, especially over the wall if possible, and try to get him into the Pit as well if I can get in close enough to do so. Keep off the Flipper and away from the Arena walls when I'm not underneath him myself, avoid hazards unless I'm taking him to them myself, and keep constantly moving and attacking from different angles.

Good luck, and hopefully that'll do it.