I was gonna make a thread on half of this before I got tired, and then of course immortius made another suggestion, so let's get cracking.
Entry Order:
For the humans, each house is progressively harder to navigate, with each Guardian being more controlling and the overall number of rooms increasing. If Housing becomes complex enough, immortius's proposal of a semi-random entry ordering makes a good deal of sense. The question I have here is how exactly do we quantify difficulty for server players? I don't think simply increasing Guardian hostility and house size is going to be quite enough. And of course, another important question is, "How do we stop players from going out of order?" Preventing the first client from just linking to someone willy-nilly will make some sense, but it seems pointlessly arbitrary in any other way unless we do it well.
There's also the concerns of my birfurcation scenarios for the Gates, but I'll detail that more as we get to the point of figuring out how entry will large numbers of players will work.
Entry Timing:
It's also worth considering that the humans didn't pull off a perfect chain of "Open Alchemizer X-> Form next connection in Chain -> Player X enters -> Open Alchemizer Y -> etc", and we might want to code some limitations as to how quickly people connect to each other. Or perhaps not. I dunno.
Secondly is the more obvious timer countdown. Dave's four hours and thirteen minutes set-up seems excessive and I propose that the timers an alchemizer makes should be limited to less than half an hour per person. A relatively simple solution would be to just say that every player will be 13 (deciding how many seconds they have) and that the number of players in the overall chain will be the number of minutes. To keep the timer perfectly accurate, we can code the entry items to not spawn until there's only seconds left to use them, or have them pull a Bottle and go flying out windows and off of rooftops.