I have just completed an install of MOSS 2007, things seem OK.

The Admin Resource Kit recommends about a dozen accounts, but this
seemed overkill for a test environment

Basically I used a "MossApp" account to perform the install and run
various application pools. This is an admin on the Web and DB server
(small farm)

I also used a "SQLService" account for DB access, and created
a "MossSearch" account that is NOT an admin to be used for crawling
resources.

What I'm hoping to learn from the group is the following:

What sorts of problems might I run into with this setup?
Which additional accounts should I consider creating to run my test
environment on.

It seems to me that the many additional accounts would be important
for hardening a production environment but for a test environment the
above is going to be OK (assuming no custom permissions needed to
index content sources) If this is wrong I'd like to make corrections
now before going much further, so please let me know what kinds of
issues I might encounter.

BTW, I did 2003 admin training with Mindsharp in the UK with Bill and
Todd (I'm a big fan) but I'm just getting started with 2007.