Hi Teroks,
These are very good questions. I’ll try to answer them as best I can, although they’re going to be short answers as I’m stopping by the internet rather quickly just now

In the Fading Suns setting (or more specifically in the Known Worlds/Phoenix Empire) high-tech is rather rare – at least compared to what it was like in the Second Republic a thousand years ago. The average person lives in an environment comparable to Victorian England – the poor enjoying very little tech while the rich have access to greater marvels. And then there are the top elite of society, the Guilds, Noble Houses, and Church Sects, who between them hoards most tech items and infrastructure. Few high-tech bits trickle down into the rest of society, although occasionally you may find the od trinket even among peasant communities and such – ancestral treasures, often revered as magical, that gives the tribe or village en edge in the dark world; and which they try as best they can to conceal from the elite, less the priests, nobles, or guilders come and take it from them.
1) The LifePath system sometimes allows non-guilders to buy up guild skills without paying points for a commission. I cannot remember how we arrived at this, but I think there were some justification for it – my memory is just so poor. It might be that we rationale that although the guild skills are technically restricted, people aren’t so stupid they won’t pick up the odd skill at beginner level when then encounter technical things. Therefore, Freemen (and even Nobles or Priests) sometimes get such skills in the LifePAth system – why we decided they didn’t need to pay the Benefice cost for a Guild Commission, I’m not sure…
As for belonging to a guild, it should be noted that ALL guilders belong to A specific guild – there is no such thing as general league membership without belonging to a guild. The reasons for joining a guild are largely social – in an unfree society where every faction grabs whatever power it can while also defending their privileges nail and teeth, belonging to a power factions is a major advantage in life. You wouldn’t necessarily have access to the faction’s resources and such (although you might have!), but you would enjoy status in society as a member of the faction and you would also enjoy protection by your group in many situations. In other words, the “reason” for belonging to a guild is largely matters of roleplaying and interaction with the setting. The faction is a major patron, but will also place demands on you.
Also remember that if you belong to a guild, noble house, or the church, you are among the very top elite of society – among the top 5% or so – and even Freemen have greater rights and opportunities than serfs; it is good to be on (or near) the top of the food chain.
2) Freelance belong to the top elite in society, albeit at the very bottom of the top elite. The nobles, guilders, and priests take great pains to keep the masses down, denying them tech and power, or else they might rise up against the elite. A serf would often be forbidden by law from owning or operating high tech stuff, but a freeman would have fewer restrictions. As part of the elite, Freemen could have access to high tech including Think Machines (i.e. computers).
3) No-one choose to be part of a noble house. You’re born a noble, or you marry into a noble family, or, in very few instances, you’re adopted into a family or raised into the ranks of the nobility from more humble origins as a reward for some extraordinary service. The nobles are arguably the strongest elite faction; they enjoy the greatest freedom (i.e. they have spare time for adventuring and such), they are universally allowed to carry arms (they’re even expected to), and they possess the greatest wealth, resources, and land. Again, it is largely a matter of belonging to a group.
Does this help?

(ok, so perhaps it wasn't a short reply after all...

)