Jay and Bill have fairly different styles, which leads to a lot of divergent opinions on this board and elsewhere. I feel that Jay was more animated, whereas Bill focuses more on describing the game. Both have significant pluses. I'd agree that Jay Howard's personality was the major issue that lead to a parting of ways.
This is a part I really have to disagree with. Bill and Pop seem to have a good relationship and talk quite frequently. As you said, the access/interviews may not be quite the same that Jay had, particularly on air, but that has a lot more to do with decisions that were made on various levels than to do with any personal relationship. Pop simply doesn't like to do interviews in most cases, which is the main reason the pre/post game interviews with Pop were canned. Obviously I can't read Pop's mind to tell you one way or another how he feels about people, but I've neither seen nor heard any signs to indicate that your last sentence is true.