Hi! Good questions. For sign-up, I would imagine it would still be first come first serve, but at least it's not gating out those of us who can't camp a computer and feels far more fair. Your example of a fire fighter is pretty much my work life. I'm a Registered Nurse and I'm busy with it for a solid 10 hours per shift with zero time to faff around with my personal phone let alone finding a computer somewhere to check Second Life.
I could see them implementing a time limit on reservations so it doesn't hold it up forever. On the other hand, when someone is near the top of the waiting list, perhaps inworld and email notifications to get someone's attention? I wonder if it could even give the premier member an option to pick a date/time window and if it's missed, then the home goes to someone else... just random thoughts. I'm not a programmer and have no idea what's actually feasible.
For alt/versus non-alt, I would guess at IP address, but then again, see above. Not a programmer. I was unaware that people are paying for premium on alt accounts as well, so that does put a different texture on it. Still, with a limited availability, promoting these premium homes as one of the major incentives for increasing the cost of premier membership, gating out those of us who do not live/work at computers on the daily feels inequitable to me and demotivating for continuing my premium membership.
As to people having multiple alts, on Plurk I've seen people sharing that they have 3, 4, even 5 premier homes between all their accounts. It's frustrating to me when I can't even get one, thus this post.
Thanks for the congenial discussion.