As for the material: Even ten years ago EMT, as well as other metal electrical stuff, were allowed to be 'protected' by only a coat of paint. UL changed its' standard, and now requires at least a minimal zinc coating. It's still possible to find plenty of non-galvanized EMT in older installs. Remember, "paint" can also be a clear laquer. I believe that UL also began to require the materials to pass a second, more demanding corrosion test.
For that matter, there were / are various PVC coated pipes made that have no zinc coating under the PVC. It's quite possible that even rigid conduit was once made by someone with only a PVC coating; it's pretty hard to make an all-encompassing claim on this point.
Bear in mind that there are a variety of methods of coating metal with zinc, with differing amounts of zinc leading to different amounts of protection against corrosion. The state of the industry is such that one cannot assume that both sides of a pipe are coated. I am avoiding the use of the word 'galvanized' here, because the term is sometimes used in a general way, and sometimes as a specific reference to a particular method and coating thickness.
The fittings need not be compression type; many set-screw fittings are listed as 'concrete tight.' The information ought to be on the box. Weathertight fittings are considered 'concrete tight,' but the packaging will not specifically say this; perhaps the White Book expands on this point.
It's my observation that it's not simple moisture, or even alkaline soil / concrete, that causes metal to rust. Rather, it's a combination of moisture AND air. I have excavated many buried EMT runs where the pipe was essentially without corrosion- until it got within perhaps 6" of the surface. At that point, extreme corrosion occurs.
Confounding my expectations, simple 'pipe wrap' tape really does appear effective at preventing corrosion.