The Rotorcraft Flight Manual (RFM) is a very important document. The Operating Limits section is law, and it is a violation to breach these limits intentionally, and actionable in any case.
The rest of Part I - normal, emergency procedures, performance - is informational and recommended, but not per se required by law for the typical pilot, but is often referred to in the Part 135 manual as the company procedures, and thus becomes mandatory for commercial pilots.
Most manufacturers chose the words carefully, and do try to provide real procedures, not just cover-your-butt words. If in doubt, call your local rep for the manufacturer, and you will get the straight word.
By all means, do not treat the words as legal constructs, and try to sneak around them. Example - A ppruner once advocated working around the crosswind limits of a helo by pointing into the wind, beginning a takeoff then pedal turning to the cross wind to complete the takeoff - he argued that once in the takeoff, the hover restriction no longer applied. Such constructions work in Congress, but will get you a healthy fine, should the investigator who visits you in the hospital after the accident decide to violate you!
Generally, the accepted general procedures, training guides and advisory circulars that are out there are useful in supplanting RFM procedures, or in helping find suitable alternatives. Usually, the aircraft are not so very different that a typically common procedure will get you in trouble. If so, the RFM will usually tell you so, to help you avoid the problem.
The FAA reads the whole document, and specifically signs the Part I (Op limits, Normal, Emergency procedures, Performance) so they have "bought" every word. They read Part II, descriptions, but don't specifically approve it (they do comment, and a dumb manufacturer ignores these helpful suggestions!)
Nick
PS Hello Rick, how's the flyin? We are going up to NE Region next week, hoping to come back with an FAA Type Cert. JAR and Transport Canada next year. Snow and Cold in January, rotor icing next fall/winter.