Could somebody please explain a little bit about the trust system on Bitcointalk.org please?
http://lmgtfy.com/?q=marketplace+trust+site%3Abitcointalk.orgIs it a bit like Ebay feedback?
No.
Is it a good reflection of the account holder
Not necessarily. That depends on how well you set up your trust network.
or could it likely be faked etc?
If your trust network includes people whose opinions and feedback you don't trust, then the score will not be reliable.
As for written feedback outside your trusted entities, a user can easily create as much fake feedback for themselves as they like.