Kubuntu 7.04 update to Ubuntustudio

[Det]

Hello all,

I am new to this list.
I had some Linux experience a good while ago (Suse 6.3,
Debian 3.0) and want to step in again now with

a) Kubuntu as my standard OS for daily work.
b) Ubuntustudio for hobby stuff, especially homerecording.

As I currently have Kubuntu 7.04 installed on my
laptop and no other machine available right now,
I hope to upgrade Kubuntu to -studio  with the hints
in:
https://help.ubuntu.com/community/UbuntuStudio/UpgradingFromFeisty

First:  Is it right that I can leave ubuntustudio-desktop from the
package list to get a full system (including low-lat. kernel) with
my beloved;-) KDE?

Must I expect problems with the low-lat. Kernel and therefore
make a backup of the current one (or is it installed in parallel)?

Second:  The page lists the package 'ubuntustudio-audio-plugins',
while it is named  'ubuntustudio-plugins' on the page:
https://wiki.ubuntu.com/UbuntuStudio/PackageList
What's right?

Third:  How are experiences with USB devices, like
mixer with USB D/A converter (I have a Phonic PHHB17) and
USB MIDI interfaces?   Do they work seamless?

TIA
Dirk