The little I know,
I get that you are trying to convince everyone that today’s “OTD” children are not in the category of baal aveira/sinner/kofer/heretic/whatever who would need to be rejected halachically. I believe, however, that there is a big disparity between the philosophy you advocate here “in the name” of the gedolim and what the gedolim would actually hold. You argue that boundaries should be set in theory, unless they – heaven forbid – make the child feel rejected, because the child’s feelings trump parental boundaries. You then bring numerous anecdotes of gedolim advising parents to not kick their children out of the house. Nothing in these anecdotes show that the gedolim told the parents to remove all boundaries in their homes, to remove any rule that might offend the child’s delicate sensibilities. Taken the way you present it, a child can hold his parent hostage on any boundary. “You don’t love me because you won’t give me ice cream for supper!” If, therefore, boundaries and love cannot coexist, and love is paramount, then boundaries must go.
I agree with you that a parent should always demonstrate to his child that he loves him, will always love him, desires to support him, and will not give up on him. Connection – not commands. This is not the same as having no boundaries. Parents who have no boundaries are not parents. They are avoiders and negligent.