I have to agree with everything you said here Steve.
I don't think that Plant hates Coverdale in the true sense of the word.
I have the Coverdale/Page CD and Pages guitar is smoking hot on there.
Page has his best muse on that disc then on anything else after the demise of JB and LZ, IMO.
Page has nothing but good to say about Coverdale. He said in an interview somewhere that Coverdale is a very nice man and it was a pleasure working with him.
Just my opinion, and I'm sure all you Plant lovers will be throwing tomatoes at me for saying this, but Plant has a hard time NOT bashing anybody else. He does it all the time.