>4. Was Ry Cooder's "Bop Til You Drop" the first created-in-studiomulti-tracked rock album to be done all-digital? What were some other early all-digital rock albums?
"Tusk" by Fleetwood Mac (1979) was a very important one; the fact that it was all digital was picked up by the press and that led to a strong anticipation for the album. I'm sure it charted, but I'm not sure it made it to No. 1, as in addition to being a pioneering effort and a splendid album it was also the most challenging and uncharacteristic LP that Fleetwood Mac ever made, and audience interest in the thing did drop off rather rapidly.
Tusk was recorded to analog, but was one of the first to be mixed simultaneously to analog and digital
http://xepadigital.com/bio.swf
I just read Mick Fleetwood's biography, and he describes Richard Dashut assembling teh 20 second tape loop of the main riff of "Tusk", and helping to hold the loop up while it was dubbed from one 24-traxk to another, as well as recording the USC Trojan marching band at Dodger Stadium for the backing track. All signs on the net point to "Bop", though I did find one report that Steven Stills was the first to record a major label all digital album, though it was never released
http://www.gearslutz.com/board/so-much-gear-so-little-time/45961-first-commercial-digital-recording.html
Stevie Wonder and Herbie Hancock were early adopters of digital technology
http://www.sony.net/Fun/SH/1-21/h2.html
5. What was the first all-digital (digital basic tracks, digital master) recording to hit #1 on the Billboard charts?
Sorry, can't help there, I've gotta go back to work, but here are a couple of links I found that might be useful:
http://www.spiritus-temporis.com/compact-disc/the-aad,-add,-ddd-code-for-audio-cds.html
http://www.head-fi.org/forums/showthread.php?t=71113
-Matt Sohn