since I'm new in BB, never done this upgrade before, and reading those posts above, could someone help me out?

-- Can this latest version transfer picture/ringtone (especially mp3) directly from PC using USB? (my Desktop Mngr is already v4.2)

-- If there is problem with Opera, then what freeware browser will work?

-- If there is a problem during installation, how can I recover my current s/w? (i don't have the original file)
Currently: v4.1.0351 (platform 2.0.0.143)

-- where is the location of vendor.xml?

Many thanks.