the ActiveSync client on the H/PC is designed specifically to initiate remote syncs, it's use for Serial sync's is trivial. PC link was meant for that.
http://www.hpcfactor.com/support/cesd/c/0012.asp
Under Windows Server the machine name is the one assigned to IIS. The only way to change the pointer is to use a DNS A-Record or a DNS C-Name.
IIS then uses a host headder lookup to filter out the request and send it along to the correct site.
If you are seeing the "No site configured" error it means that you are hitting the server's IIS Metabase and the metabase is replying that there is no website configured for unbound, open port access on TCP 80.
You will need to access the site using
http://<hostheadder>/ which has a DNS registration on a DNS or WINS server that is accessible to the Windows CE device. If there is no active registration either of the LMHost, DNS, WINS of the secondary name then the H/PC will not be able to access it.
#3 could be down to a too restrictive security policy either in the LMP or GP. You have to use UNC to access it not HTTP remember as outlined in the CESD.
http://www.hpcfactor.com/support/cesd/c/0006.asp
Typing just the server part of the UNC without specifying a share will display a list of all avaialble shares on that particular computer.
Accessing web server shares should be done via FTP or via a read only directory browse setting configured in the IIS Metabase.