Do you need multiple accounts on Vista ?

I normally work under a domain user account, DEVELOP1, for development with
VS2005 on Vista Ultimate.
I prefer to use the Microsoft "policies" regarding user account control so I
installed the system under Administrator. Then you are required to enter a
new user,I used "ADM" with admin priveleges.

Now I have practically 2 accounts that I work with DEVELOP1 and ADM.
Problem #1 is that when I want to use VS2005, you are advised to work as
administrator. So right-click VS2005 and select run-as-administrator. So far
so good. Nuisance at the moment since you tend to forget and then you are
prompted by VS2005.

However when I want to install a program or want to check on windows setup
you need to do this under your ADM account. So I switch users from DEVELOP1
to ADM. At the moment I keep my ADM account running in the background and
switch accounts when needed.

Q: Is this the way we are supposed to work with Vista?
Q: how can I make my domain account (is already defined as administrator in
Active directory) to become a local administrator on my notebook, so that
do not have to switch accounts to satisfy Vista.
Q: if you use OneCare you need to keep your ADM account up and running since
tune-up and back-up can only be started from that account.

Advise is appreciated.
-Eric