Holiday Blues Scrimmage

Have you tested it before?

Sounds like a great little idea there, but... I can probably infuse myself out quicker than most people will notice. On top of that, everyone is just going to start to infuse out as quick as they can, meaning they will not have time to heal everyone, which will just turn into a race of who switches sets quick enough.

Sounds like a good idea, but I think it would be pretty broken.

Couldn't you just have 5 sup runs + a 60hp set, infuse, switch to -50hp set?

Well that's the beauty of Infuse Health, it will give lots of unwanted HPs to your opponents, so be ready that your hp might not drop as quick as you want.
3 Infuse and you would be at 10% hp, I'm sure others would have countered it by now. As energy running low from Infuse spam, other skills are needed but they all have their backsides.

I haven't tried this myself though so it can be open for tweaks and improvements. Most important if you replace skills is to pick skills that can backfire on you, for example enchantments that benefit you but same time make Dwayna's Kiss better. Watchful Healing perhaps?

This would be pretty fun I guess, its all about quickly responding to sacs of others right? I think the rune/weaponset part can be overcome easily with standart costume in the arena and you get only 1 weapon enables which drops in front of you at the start of such match, if Anet decides to implement something like this. It would be pretty funny and something new I think ^^ Though you might get bored of it quickly. But original approach, really like it ^^

Maybe use the DoA environmental effects?
Edge of reason is a nice one because the 3 sec recharge it adds
(i.e. no brainless infuse spams)

In anyway it's not a serious World Champion Pro event, mostly just something fun guilds or friends can do when they get bored
Besides remember aftercast adds plenty of time to react .. 3 Infuses takes 3 seconds total, if others fail to react in that time they're either stoned, drunk, dead or busy with other things.