When you run the proxycfg tool, what switches are you using? I normally
run the following:
proxycfg -d -p fakeproxy:80 "*;<local>"
It works fine for me after running this line.
Also, it all depends on what your requirements are for SharePoint. Both
SharePoint utilizes Outlook in some form or another but the differences
between SPS and STS is that SPS has a document management system (check
in, check out, versioning, discussion) and STS doesn't. STS is more
geared toward a department, division, group, team, etc within a company.
Project 2002 interfaces with STS only because it can only view the
document vault of STS and has no interface with the vault for SPS. I
view STS as SPS lite, it's just a lesser version of SPS.