Std edition license details

Hi,

I understand that CS2007 std edition is limited to a web farm with 2
servers, but is this only the runtime system or does it also apply to the
administrative web service applications?
We would like to move the WS apps to a server in a different zone (and to
remove the extra WS load from the front end production servers), but this
would involve instaling CS on a third server. Would this WS server require a
CS2007 license, and if so, would all three servers require enterprise edition?

On a similar topic:
As the site evolves extra brands/sites may be added in the future. I
understand that one CS site can only have one runtime application in standard
edition. If you simply configure IIS to map to two different web sites to the
same physical directory, will this be a violation of the license?

Finally:
Standard edition supports up to 10 Commerce sites, and this will be fine.
However, is it allowed to use one physical Catalog database for all sites (by
simply using the same connection string)? And also for the other ressources?

Any help in clearing up these issues would be greatly appreciated as I have
a hard time fully understanding the licensing details.

- Lasse