Question About Tablespaces in Windows Environment under PostgreSQL 8.0

One of the environments we are using PostgreSQL 8.0 in is Windows 2003,
single-disk, non-logging environment.

- Can somebody comment on the advantages of using / not using pg_default vs.
a separate tablespace for non-template databases, outside of the ability to
control separation tables and indexes into two separate tablespaces, etc. ?
Are there any disadvantages outside of not being able to place a tablespace
on a separate disk?

- If I do not use pg_default, how do I get the file system attributes right
for a new tablespace? Being as the installation is to be completely
automated, does anybody know what DOS commands (like ATTRIB) have to be used
to set up a new tablespace location (directory) properly for PostgreSQL use?
Are there considerations as to what user the .bat file install file is run
by, being as it seems that PostgreSQL prefers that the username under which
an install is done may not be the same username that exercises the DBA
functions ?