A guild (by most definitions) is an in-game collective that controls both in-game currency and resources, pooled by the members of the group.
By that definition, it is something Frontier are adamantly against.
However on your other points
It allows you to create a Wing (ergo guild).
I would dearly like to see the player minor factions become something you could join and be identified with (a clan rather than a guild). They would need proper group management tools. In an ideal game, their own voice chat channels.
It allows you to create a Squadron / Flight, e.g. dedicate players to specific roles... e.g. a mining squadron, or pirates, or bounty hunting.
Personally, I don't see any point to this. I am a miner on Monday and bounty hunter on Tuesday. Will I be an explorer or trader on Wednesday? Why pigeon-hole myself?
It allows you to create Missions (e.g. events that other members can sign up to)
Community generated missions. Absolutely! For 1M Cr kill CMDR Kerrash! Station gets 5% - player setting mission pays total. (Sorry John)
It allows you to upload your Elite .log file to generate a Flight Plan (showing systems you went to, stations you docked at, interdictions etc)
Nice to have, especially when try to work out where that lucrative trade route from last week was. But to record AND KEEP that level of data for nearly 2 million players (Inara is only 18K). Well that adds costs.
If they could make it a feature that stores data locally, hell yeah!
It lets you set up a quick overview of your pilot (e.g. my signature below).
Isn't that the status TAB? We already have that.
It lets you form a coalition with other Wings (guilds) to work together.
Kind of straying from what games generally do. Nothing to stop in game chat organising things though.
It even has a logbook feature, where you can type in anything from a few words of what happened that day to a long entry of thoughts and ideas.... and you can share the logbook with others, or keep it private.
We're now in Facebook rather than Elite territory here. Sure, nice to have, but there are a billion things I'd rather see in game first.
It has nice discussion forums
Isn't that what
these are? Do you really want web forums in the game? Does ANY game have this?
It has a cool gallery function where we can share screenshots.
I can't see any need for space-instagram. Maybe somebody wants it, but not me.
It has the latest news, community goals and even radio channels to listen to!
Galnet is already in game and still evolving. Who knows if the LaveRadio SideWinder will one day actually broadcast radio (ala GTA)?
In summary these things are good ideas for the most-part, but don't expect more than one or two to make it into the game for some time to come.
Inara is safe for now.