OK, Here's my foolproof Corsair system:
Go to Colorado, hang around Ouray Base and kill Xenos to get Silver
and good reps with just about everyone EXCEPT the Zoners.
Watch the Zoner rep carefully. Stop when they are going negative.
Go to Kepler, Bribe the Zoners, return & repeat as needed.
Then go hang around Dublin's Arranmore Base and kill Mollys.
(Do NOT take missions, just hunt them on your own) Kill Mollys
(Mining Gold between waves) until Bretonian reps are Green and
Corsairs are Neutral. Save. Now go to Freeport 1 in Omega 3 and
make The Corsair Bribe. Look at your reps, you should be Neutral
with the Bretonian authorities; if they're Hostile you didn't kill
enough Mollys. Depending on your current rep with the Outcasts,
IMG might be Hostile too, which is bad. In either case, go back
to your save and tweak the reps. If you do this right, the only
new Hostile you will see is Bundschuh. Bundschuh are sympathetic
to Xenos & Mollys, but unlike Zoners their opinion don't matter
Red Hessians might also be Hostile, depending on your rep before
the bribe, but this doesn't matter either since to get better
rep with Corsairs you may be taking missions against them.
(Much safer than taking Corsair missions against Bounty Hunters!)
Corsairs are good for weapons & shields, but I don't like the Titan.
Corsairs: If you are interested in the Storyline, enquire about their
two secrets _before_ you get full green with them. Once you get
full green they just drop hints you should leave. Their Secrets are
revealing, but not as creepy as the Outcast Secrets.