TAXES - U.S. expats (Jeddah)

Hello --
I seek advice from U.S. expats working in Saudi Arabia, who have had the experience of filing U.S. income tax forms.

I have just started working in Jeddah. I want to be sure I understand my potential U.S. tax liability. Specifically, I have encountered 3 different perspectives, concerning the requirement that an expat must stay away from the U.S. for Protected content days, in order to avoid paying U.S. taxes on income earned in SA. Note: I will be making less than $80K per year. (I have heard $80K is a magic number.)

Can anyone tell me, which of the following is true: Protected content must not step outside SA for Protected content , (2) it is OK to travel outside of SA, so long as I do not set foot in the U.S. for Protected content , (3) I can visit the U.S. during the Protected content interval with little risk of having to pay income tax, simply because no authorities will *check* to see whether I have set foot in the U.S. or not; i.e., it would only be a problem if ever I were the target of an audit.

I will be very grateful to any member of the InterNations community who can shed light on this for me. Thanks!
---Susan