Vista Admin Queries

I need to get a new laptop, but have never liked some of Windows XP's
"features" - mainly

that it often thinks it knows what I want better than I do! I'd like to find
out about some

things in Vista before going with that though, in case it's even worse than
XP (which it may

be if some of what I've heard is true). I currently use Windows 2000, as
that was available

at the time and I much prefer it to XP.

Windows 2000 has "Power Users" as well as "Users" and "Administrators". I
have found that

some applications (mainly to do with software development / debugging) do
not work when run

as a User, but do work for a Power User. Hence I have always logged in using
a Power User

account (not wanting to run as an Administrator all the time!) I have set XP
up with

separate User and Administrator IDs for friends, but they have usually ended
up still always

logging in as an Administrator, having found that some of their software
doesn't work for a

User. I understand Vista does not have Power Users either, but are Users now
able to do

more, or am I going to be forced to log in as an Administrator to use some
software?

On a similar issue, I have seen some posts on these forums suggesting that
even

Administrators are usually only Users for most of the time, and are asked
for Administrator

access when programs need it (as are normal users). If this is the case, is
there actually

any point in setting up separate User and Administrator accounts? It seems
to me that there

is no real difference.

Also on these forums, I have seen several reports of Adminsitrator users
being denied access

to certain files and directories. Is this supposed to be the case? Sometimes
I find it

useful to be able to alter or replace (possibly corrupted) system files to
fix problems

without needing a complete reinstall, or to remove stubborn viruses.

I have also seen mention of a built-in Administrator account, and
suggestions to give it a

blank password in order to avoid having to type in a password when prompted
for admin

access. Is this not a security risk? If nothing else, Vista presumably still
has the hidden

C$ etc. shares for each drive, which would then be accessible by just about
anyone?

Thanks,
Mark