popa bar abba- I have been reading many of your comments on these threads and most of the time, you are quite rational and instructive. But your assertion that there is no difference between d’oraisa and derabbonons (that is the gist of your post) flies straight into the face of every halocho. Did you know that there are more flexibilities with derabbonon than d’oraisas? An example- “stam jeinom” (a derabbonom) is bottul beshisha (1/6)- real jajin nesech (a d’oraisa) is not. There are a plethora of halochos in joreh deah that will use various ‘snifei hetter” if it is a derabbonon. How about the hilchos aveilus? we pasken that we go ‘lekuloh” because aveilus (after the first day)is derabbonon. And many,many others.
It is actually of crucial importance to know whether something is d’oraisia or derabbonon. it is not to say that one should not follow both in same fashion but there will be some very definite differences if covering a woman’s hair is only derabbonon, starting with the Aruch Hashulchan’s hetter.
I understand your feelinsg that you want to follow your ‘rebbeim’ of the past hundred years but you must understand that this is not how Poskim look at it. They have to go back at the origins of a halocho and understand the issues discussed. Another example: shaving on chol hamoed. The Nodah bejuehuda had to interpret a MISHNE to come to his conclusion. You cannot get earlier than that!
Nonetheless, I have found this thread very stimulating both in its discovery of various ways of looking at a certain halocho and at the people who are responding.