Chief G..... the use of "recommended" is an attempt to change the culture of the Australian pilot.
In the USA, if a procedure is "recommended" then it is likely that you will see almost total complience. However the culture in this country is that to get the same results it must be mandated.
With your second point, remember that a CTAF is a procedure and not a block of airspace even tho it may be given dimensions. Good airmanship should dictate that calls in a CTAF should relate to the speed of your aircraft and what needs to be sorted out from the time you make your first call. This I suggest should always be time based, and I suggest for most operations it is about 7 minutes out as a min.
As for making calls when at low level, there is no need unless you are going to use such a landing area. If you are down in the sticks then monitor 126.7 if a bit higher, then center or FW. Remember it is just recommended!