Vista and XP

cloned my original XP hard drive (1) to another hard drive (2)
shut off 2 in setup and left 1 on
updated 1 to Windows Vista Beta 2
have been playing around with Vista - and enjoying it FWIW
turned drive 2 on and it shows up in Windows Explorer - all is well
copied a few files from 1 to 2 for back up purposes - and to see if I could
do it - I could
I am now curious:

1. mm I likely to damage HD2 (XP) in anyway by having it on along with HD1
(Vista)?
2. can I turn 1 off in setup and boot to 2 and work in XP?
3. when Vista boots up it shows something about a Windows Boot Manager - is
this something I can use to decide which HD to boot to?

All in all - I have been happier with Vista with each new thing I learn

TIA

Bill