In answer to the first question, this is the process I use for authentication in Windows: http://timgolden.me.uk/python/win32_how_do_i/check-a-users-credentials.html
Another user posted this excellent LDAP setup tutorial: http://ochiba77.blogspot.com/2011/10/how-to-set-up-web2py-ldap-with-windows.html Someone else will have to chime in about your other issues - I'm running against 2005SP3 without issues.
