Well, as I said before: congratulations. You've put some thought into this.
I find that Sony mics (..in fact many Japanese mics..) sound a bit "thin", and your Sony ECM-Z37C has a frequency response of only 100-10,000Hz (and it's mono), meaning that although the camera shoots a great HDV video picture, the sound will be only 'half there' (it's mono) and there'll be no bass, and not much 'top' ..so the sound will be rather like that from a good quality telephone.
Your 'shotgun' mic, too, is mono, so although its frequency response is far greater (30-20,000 Hz, meaning more bass at the lower end - down to 30Hz instead of 100Hz - and more treble - up to 20kHz instead of only 10kHz) you're still getting only 'half' the complete "width" which a stereo mic gives.
Don't worry! ..But be aware that if you're going for good
video, it's also worthwhile going for suitably good audio to complement it. (After all, you have chosen to get a high-definition camcorder..)
It was an excellent idea to get a wide-angle adaptor. Your 0.7x adaptor gives something like an extra one third width to the picture, which you certainly need indoors.
Your comment that "..the demise of DV tape is not imminent and that the hard drive and DVD camcorders are aiming at slightly different markets.." is spot on! Diesel engines were put into cars because they were cheaper to run, a bit more 'robust', and don't have electrical problems ..but that hasn't killed petrol (gas) engines.
I don't have time right now, but in a few days I'll put up a comparison QuickTime movie of sound from an HC camcorder, a Sony ECM mic, a little Vivanco 'Lavalier' (tie-clip) mic and a couple of Beyer mics, and then you'll be able to hear the differences between them ..and the differences between recording in mono and stereo. (Different stereo mics can have quite different sound characteristics.)
"..B&H recommended Panasonic AY-DV63PQ Prof 63 minute DV Tape for recording.." ..I don't know if it still applies, but it used to be the received wisdom NOT to mix different brands and types of recording tape, because different manufacturers (..though sometimes brands are the same tape, but in different wrappers..) were said to use different - possibly incompatible - lubricants in their tapes. By mixing tape brands it was possible to "gum up" video heads, as the different tape lubricants didn't "play well" with each other, and could cause head clogs.
I mention this because the 'Professional' tape is much more expensive than general purpose (Sony, JVC, Maxell, Panasonic etc) tape, and you might be tempted to change after a while to a cheaper type. Try to stick (no pun) with one brand and type, and that should avoid head clog.
Your G5 iMac and 2GB RAM
may be fast enough to import HDV material at "real time" speed, but be prepared to find that your Mac isn't fast enough, after all, and that importing
HDV may take up to twice as long as "real time" ..so importing half an hour of HDV from the camera may take an hour. (That doesn't happen with normal standard-def DV.) It's because your Mac has to convert the HDV footage "on-the-fly", while it imports, into a format which iMovie can edit (..it's not editable in its native MPEG format on the tape).
If you start to shoot a lot of HDV, you may later want to think about 'upgrading' your Mac to a faster machine.
For a few other general hints about Shooting, try these
Shooting Hints, here..