Coretemp should do the trick for the cpu temp...dunno about the rest. Just remember that it overestimates temperatures by about 5 degrees compared to mobo bundles.
I got a feeling that temp 3 could be the northbridge, as mine tends to run warm. No idea how to fix it without adding a fan tho.
Thats the thing.. I also have an asus board with no fan. Find it strange the top of the line asus board has no cooling, but their heat pipe instead.
This is somthing that has only started in the last week as well. Been running without any problems before then. I even had 6 hard drives installed, but have
pulled all those out (well 4 of them) to try & solve the issue.
I dont use a case lid, but now have a Deskfan setup in front of it & its stable.