I somewhat anticipated your answer, and appreciate the explanation. I am aware of advantage/disadvantage philosophy and try to apply it as much as possible. One of the problems I have is with the classification of fouls. To my knowledge, there is no official document produced by NFHS that categorizes which fouls are safety-related, which are advantage/disadvantage, and which may be both depending on context. I am also unaware of any official word from the NFHS regarding the advantage/disadvantage philosophy. If you have some FED stuff, I would appreciate a copy of it. I'm also kind of reluctant to embrace NCAA principles at the High School level for several reasons, one of which is the difference in the codes. While many principles are beneficial to us "lower-level" guys, some are fundamentally different.
As to all the different situations when B can be called for blocking in the back, I would suggest that just like a LB can "cut" a pulling guard, he can also block him in the back, preventing him from executing his block, allowing a teammate to make a tackle. a defensive player can hit a receiver behind the line waiting for a screen pass in the back, preventing the player from catching the ball. It's not DP, not illegal use of hands, not defensive holding, but is certainly a foul, because the defense can't block in the back.
You missed a Defensive Holding situation. Much like the block in the back against a receiver behind the line of scrimmage, if the defensive player tackles the receiver before the ball gets there, I believe that's a foul for holding.
Anyway, I appreciate your comments and your philosophical approach to officiating. I've learned a bunch as a result of your posts. Thanks.