I have a problem with my reputation. I only have a good reputation with the Kilrathi and the Merchants. The rest is in the red area, since I did the plot missions for the pirates...

Is this normal? Can I somehow change it?

Would be nice to get some answers, thanx.
During the pirate plot missions, I did not shoot anyone, instead running for the nearest base. I did not have any problems with the rest of the people once I was no longer a pirate.

A general rule with regard to reputations:

Nothing is permanent.

If you are in a hurry to fix up your faction ratings, head to Oxford and kill a lot of Retros.
thanx.. the tip with oxford helped a lot..

however, I am also at the Oxford mission now and I can't seem to get the drayman safely to Planet Oxford...
There are just too many of those demon hunters.. any suggestions (since I cannot buy missiles for my demon this might be a problem Oo)....
You'd be hard pressed to find a player here who didn't have a problem with the 3rd Oxford mission.

Here's a thread that was made some days earlier and drew a lot of attention. The discussion is mixed (a lot of talk on demons and how they are unbalanced, for example) but there are some (vague) strategies on how to beat it.

I made a post towards the end of the thread as well, essentially my advice was to just keep trying. The difficulty of the mission is not constant, and sometimes the mission is just messed up. Once or twice, the drayman was destroyed mere seconds after I launched into space from Oxford.

Good luck.

Oh, by the way...the hunters will dislike you for a time after you finish the Oxford missions, as well as the set of campaign missions that comes after them. The solution is to kill Pirates and Retros.
ahhh, ok...

Now, I have just one last question?

I have bought the 400000 credits model of the Centurion and I can't see the specs for engine/shields and so on.. I even can't sell them.. is this normal or do I have done something wrong?
You bought a "milspec" Centurion. It comes with a default reactor and shields, so they are automatically repaired when you buy a "Basic Repair".

Milspec ship versions have caused much confusion and will be removed in the 1.01 patch. I suggest, if you have a save game right before you bought the new ship, to load that up and buy a stock Centurion (the cheaper one). Then you can upgrade it as you see fit.
One last question:

There are Heavy shields and heavy reaktors: Do they fit on Centurions, or are they only for the heavy fighter?

I'd like to know that and do turrets operate automatic or do I have to command them all the time?
They fit on more heavily defended ships like the Orion. Don't worry, the Centurion is as mean as you can get in Privateer Remake ( soon as we balance that Demon). You don't need level 5 shields to lay waste to squadrons of pirates and kilrathi.

You can switch to turret view to command your turrets. Or you can set them to 'weapons free' mode with cntrl+w (turn off the mode with cntrl+r). The most useful key for turrets is Cntrl+t, which tells your turret gunner to fire on your current target - it works much better than weapons free mode. You can select a hostile target, cntrl+t, and then switch to another target and let your turret(s) take care of it.

And, just so you know, turrets have their own reactor. The recharge value and storage capacitor is listed in the description. Having your turrets firing constantly in no way impedes your ability to fire your primary guns from the cockpit.

Enjoy! In the Original Privateer, there was no turret AI (you had to control them by yourself).

Is there anyway to improve your stainding with retros? Or are they just the red-headed step children of the Universe?

Also, other can communicating and pressing 3 repeatedly is there anyother way to improve standings with the other factions? I can get Kilrathi and Pirates to Zero but how do I increase it past that?
You can't make friends with Retros.

Best way to improve standing with a faction is to kill it's enemies.

Just keep killing Retros and eventually everyone (except the freaks) will like you, though it'll take a while and will make the game rather pointless and boring.

I usually keep hostile relations with Retros, Kilrathi, and Pirates. You end up killing them on mercenary missions anyway.