I like Freelancer Trader associations, but there are some obvious contradictions - you want to force the corporations off the market through harassment, but aren't you at the same time planning to use those corporation's bases and commodities for trade? Besides even though Ageira and so on aren't represented by many players in-game, they are supposed to be huge corporations no Freelancer Trader group will be anywhere near taking a stab at.
I think you would be better off either being fully "shady" and neutral to pirate factions as well as corporations, or fully law-abiding - if I were you, I'd keep it simple to begin with. Just be a group of independence-loving traders, find some good/interesting trade routes with interesting people and groups to RP with, and take it from there. Security and underworld dealings is something you can add later on.
This is taking things in a different direction, but you could also make a USI ID'd faction focused on freedom and independence and have Xenos as your main clients; you'd of course have to be sneaky about it but it could give you some fun "grey area" trader-RP. Black Market Munitions from Rousillon to Milford is super profitable, and you get to RP with two fun groups ([C] and XA) along the way.
