Well, each of the current Generic IDs has various pros and cons, so new Generic IDs could be put in and fit to those roles. I'd suggest revising them all a little bit, using this chart as a guideline:
Suggested Name
Default Legality
Benefit
Loss
Freelance Mercenary
Quasilawful
Can claim bounties
Bounty necessary to attack
Freelance Pirate
Unlawful
Can pirate most things
No-dock to quasilawfuls, hostile to corporations and lawfuls
Freelance Miner
Lawful
Mining bonus
No-dock to mining factions, hostile to pirates
Freelance Hauler
Quasilawful
Cargo up to 4,300
No-dock to corporations, hostile to pirates
This way, the names are more uniform, and it kind of demonstrates that all generic IDs are really Freelancers. Thus, they'd all get the Freelancer IFF by default. Also, this suggestion is only a rough sketch, so discuss
Nota bene: By "pirates", I mean pirate factions such as LH, LR, GC, etc. and most likely terrorist factions as well, like the Gaians, Xenos, etc.. Miners and Haulers would likely still get access to Revolutionary/Activist facilities, such as Council, Bundschuh, HF Legion, etc.