If the number is truly random, which I believe it is, then the house can't lose.
The house does lose, regularly. It's down over the last few days even. Currently it's up only ~150 BTC on 22k BTC wagered. Which while not exactly losing is below expectation, and far below the "up 300 BTC" we saw a couple of days ago.
The downtime was while I moved the site to a new server. The previous one was running an old apache server, a MySQL and a bunch of other crap I wasn't using, since I previously used the same box to host dooglus.com (which is temporarily down, since it is practically content-free anyway). It had quite limited disk space, which was running out, and nowhere good to place a swap file. I figured it was best to do a clean OS install and put just exactly what I need on it. I got it mostly set up before taking the old server down, but of course couldn't copy the database over until the old server had finished writing to it. Hence the 15 minutes (which actually took 30 minutes).
Now there's plenty of disk space, and less old cruft.
I can't see clearly which of (1) or (2) is the fairer way of divvying up the player bets. On the surface it seems only fair that if MPEX-PR is willing to risk 900 BTC per roll, and the rest of us put together are only willing to risk 100 BTC per roll, that she should get to play against 90% of whatever sized bet comes in. Else she's only getting to risk the majority of her investment against the biggest bets, and that way lies ruin.
I guess I prefer (1) because I'm not in the position to risk high percentages of my bankroll. I'm already pretty much all-in. So it is indeed self-interest (as an investor, not site owner) that makes me prefer (1). (2) allows MPEX-PR to price me out of the market almost entirely. As site owner I suspect I have to chose (2) though.