Can you remove sand in the bunker, hazard, fairway, fringe or even the tee box?
The short answer is only the green. You cannot remove sand (or dirt) from anywhere on the course except for the green. Yes, the fringe is off limits. You cannot touch the sand if your ball is on the fringe in the middle of clumps of sand.
Here's USGA's explanation of Rule 23-1.
Why Sand and Loose Soil are Not Loose Impediments off the Putting Green
Q. What is the reason why sand and loose soil are not loose impediments off the putting green?
A. Sand and loose soil are part of the earth. Permitting the player to remove sand and soil other than on the putting green would inevitably lead to situations in which the player would be at liberty to remove a great deal of earth from the area of his intended swing and stance, improving the lie beyond the extent that should be permitted. Additionally, the putting green is an area specifically designed for putting and sand and loose soil are not commonplace on such a surface.