3) I am a newbie member and I have seen others post where they pay you a certain amount on this site to do certain tasks but won't accept any newbies, how do I rank up?
4) How is trust gained?
Hi and welcome.
Ad3: You simply post. That's it. Posting makes your activity go up. One post 1 activity point.
14points in total are available in the period of 14 days. Posts are unlimited.
Once every 14 days activity is added to your account, if a certain threshold is crossed
you rank up

more here:
https://bitcointalk.org/index.php?topic=178608.0Ad4: You can gain trust by interacting with other forum members. By selling, taking loans etc.
Trusted members will give you green points eventually. Or red