So erm, given the nature of the game, how is this guild going to work?
I'm not sure what you mean by "given the nature of the game" Joe. My opinion on ED's design is that it's highly compatible with coordinated piracy / bounty hunting / guarding / trade activities. ED is a MMO game and the developers' intention is certainly not to disallow anybody from crossing anybody else they don't know. On this basis, I can give you every assurance that there will be a multitude of opportunities for planned and unplanned interaction with other pilots.
I'm not sure where people are getting the idea that instancing = never meeting anyone / being able to do any kind of group activity. So far we've been restricted in how much interaction we can have in Beta, but even here I've cooperated (somewhat opportunistically) with like-minded individuals to take down cargo vessels and steal their cargo, all the meantime not killing one another; sharing in the spoils. However, things aren't only restricted to coordinated piracy. If you've had the chance to try out Theo20185's EliteDangerousTradingAssistant, you'll realise how laborious it will be to accumulate and aggregate commodity prices and stock for numerous nearby stations in star-system islands within the galaxy; a coordinated effort in gathering in this data (e.g. as a guild / clan / corps) to generate a network of trade would keep the guild well ahead of the rest.
I haven't gone into discussion about how else you could profit from a guild because I think it's naturally quite intuitive; how does a Sidewinder take out an anaconda filled with Gold by him/herself and no NPCs to help you out? Anyway, let's not detract from the simple pleasure of having comrades to chat to and flying around with you mutually enjoying the game; it's half the fun of being in a group in the first place; I'd take a human wingman over the planned NPC hired-gun wingmen any day.
The Design Discussion Archive forum is a good place to start if you're not sure what the developers are working towards with regards to ED, trading, piracy vs griefing and where the line is drawn, etc etc.