This makes a great deal of sense, there's probably some genetic augmentation to survive the rigours of space but nothing so extreme as the Belters have adopted as this might be seen as a 'perversion' of the human form and considering the Clans get twitchy when you mess up language, I doubt they'd approve of severe changes to the human form.
Yeah nothing too extreme, as you point out the self anointed guardians of humanity (the Clans) would have a real problem with aliens like themselves.
They are pretty conservative, almost reactionary, if you think about it in many ways.
I was toying with the idea of calling the Guilders the 'Spaceborn' but that might be a bit much.
Still the Guilds would pretty much have a 'Free' hand in self governance. I was thinking more today about the Guildmaster and how I see succession proceeding. The main founder I simply called Markus (no last names here) and his successors take on a variation of that name (Kamrus, Arkmus, Rukmas, etc.). Also I see his line as something just short of hereditary akin to how the Director-General of the Terran Hegemony was elected. Meaning the Guild Council elects one of his descendants either through tradition with some experience necessary - say they have to serve as a Caste Leader (Scientist-General, Merchant Factor, Master Technician, Senior Laborer).
As you said they exist only to serve the Warrior Castes of the Clans as a whole, and in a Warrior's eyes, they earn no honor or glory and are probably little better than labourours. But 99% of Warriors would never ever interact with the Guild outside of those who see them when they make deliveries etc or are escorting the Khan/saKhan when they meet with them to discuss a trade. Something tells me that the Warrior's might well be aware of the Guilds but that's it and they're more widely known amongst the Merchants, Scientists and Labor castes.
That is an interesting idea. Do you think that the Smoke Jaguar lower caste revolt on Londerholm was inspired by the Free Guilds? Or better question do Clans like the Jaguars who fear or loathe their social lessers seek to limit or ban contact with the Free Guilds? I'm sure like Ice suggested some lower castes would likely try to escape there if they knew of their relative freedom. This sounds like a good story seed for an incident with them. Lower caste escapees a historical example.
This is a possibility, perhaps some old Trueborns are given the 'honour' of acting as an ambassador to the Guild along with a small staff and again its 'prestigious' but its really a punishment.
I like that idea for Guild Keshik - ambassadors more like overseers from the Clans is sort of what they are.
On another topic which I can place here thanks to your thoughts on piloting, what do you think of the Guild sponsoring a race? Racing was an idea I was throwing around recently in my head (admittedly as a Davion Outback pastime of Mech racing with NASCAR parallels) but it works here too. What if the Free Guilds prize sporting event is a race, perhaps again inspired by a historically event like the Pentagon Run or something? It would give their expert space pilots something to compete against each other in (Clan like) with no weapons of course.