Questions about sysprep and SQL server

OS: Server 2008R2

SQL 2008 Express

I am creating image, installing server 2008R2, configuring the OS, installing SQL, then sysprep.

is this healthy ? the SQL seems to make problems, for example i cant login with -E at @sqlcmd, i must use the -U -P parameters, what other affects does sysprep has on SQL server?

If when i install the server i use the same hostname as after (i define it manually prior to installing the SQL server and then i put the same hostname in the answer file)

Thanks.