Slightly off topic, but since it's starting to look like we're actually going to do this, allowing guild bank repairs for at least that evening might be a nice gesture since we're probably going to be wiping like chumps initially - which in itself is a big part of raiding - and since based on my understanding, some kind of raid progress is what the guild is aiming for eventually in the grand scheme of things, this would encourage people to take part in the fun & games.
Another thing that should go without saying: bring consumables! Pots, flasks and buff food can and will make a difference (and are also an integral part of raiding) so if we're gonna do this, let's do it properly!