Ken, I notice that there hasn't been a torrent of suggestions, so I'll give my views. First, although you apparently aren't giving much weight to it, consider a mega-changer even if you don't use all of its features at first. Note that it isn't legally required to load 400 discs at once or even to enter the ones loaded into the memory. For example, a couple dozen could be loaded and a handwritten list made of their positions. Then, when(if?)the complexity became less terrifying more of the capabilities could be utilized.
I don't use my mega-changers for some of the features that you mention, but the Sony 995, which you could get for $200 on Amazon with your certificate, does remember removed DVDs, random play CDs/SACDs(no DVD-A with Sony, of course)and has a replay button to kick back DVDs about 10 seconds. If you're interested in studying it, the Crutchfield site, as usual, has the most detailed info, including a link to the manual.
