Thanks for the confirmations and additional advice!

We've already got #2,3,4,and 5 planned out.  Well, #5, about the backups, we're going to stash those on a partition of what we expect will be unused space on the log files disk.  So it will be a RAID-1 of 145GB of which we need not even half for logs so I was thinking logs will be on f:\ with 45GB and the remaining 100GB can be g:\ and we can stuff backups in there.  Same for the spare space on the tempdb disks.  Since backups only happen once a day at night and we rarely restore they should be OK like that.

"I've never had a server with enough drive letters to do everything on that list."

When the other side of the PowerVault in question is freed up (it's a hand-me-down from a couple of servers headed to SAN land) in a couple of months, I'll have 14 disks to fiddle with and will get pretty close to being able to do it all.  It'll have to be on only 2 SCSI channels but as beggars we've been choosey enough, hah!