I reset PRAM/VRAM and SMC, as per Apple's website instructions.

I also followed "artie505's" advice and ran Apple's HARDWARE TEST. An hour and 5 minutes later, the report found NO hardware issues.

So . . . I SOLVED THE PROBLEM myself . . . ditched Yosemite.

I did a clean install and re-installed MAVERICKS. No issues at all with startup. Disk Utility log is as expected with no conflicting reports for the amount of used space and free space on the HD.

Nothing "buggy" to report at this time. Looks like Yosemite just doesn't like to play with my 4-year old MBPro (early 2011).

P.S. Should have done this from the get-go and saved myself HOURS of grief. frown