Those 80,000 people can only type so fast. A human is highly unlikely to be able to send more than a couple messages per minute, even if they are chatty as hell. Combat requires 500x the worst case human being scenario.
Indeed. but you're the mathematician, so I shouldn't need to tell you to run the numbers.
80,000 chat users x 2 per minute = 160,000 per minute
200 players x 1000 messages per minute = 200,000 per minute
That's not a huge difference.
Now, sure, if we were supporting 150,000 paying subscribers 24 hours a day, that would be a recipe for failure. Supporting a tiny percentage of that number, spread through a series of instances, is a reasonable goal (for certain values of reasonable, heh).
Can paragon chat handle being hit by that volume of incoming messages? I have no idea. I doubt that Codewalker had that kind of wall of text in mind when he programmed it, but that doesn't mean it would necessarily choke, especially given that any individual client would only see the metadata in its environs.
Melee players actually had to sometimes lead their targets like fighter pilots to get their melee attacks to hit running targets. And in the pre-Issue 1 days when NPCs used to run away a lot it could drive melee players insane.
Ah, the good old days. Blind was one of the best reasons in the world for being an Illusion Controller. That and the fact that Ill/Rad was nerfed three times and was still one of the best powerset combos.