1) Need to configure unattend.xml file to do not ask to enter the windows product key in the post-sysprep boot. And leave the product key blank.
The only way I found to do this is by configuring unattended xml file - 7 oobeSystem - microsoft-windows-shell-setup_neutral - OOBE - SkipMachineOOBE to "true"
But WSIM online help states very clearly that this is an obsolete option that shouldn't be used on production with windows 10 as it will conflict with other options.
2) Also need the post-sysprep boot to ask for the hostname in this format: PC1234 PC is a constant, and it would be great to hardcode it, and only need to enter the numbers. This I have little clue on how to do it with an unattended .xml file. Is there an unattended option for this I'm missing?