Yes, if you select a different boot drive, your local boot partition will not not be touched.
For automation there are many command line options, see F1 - help.
I would ignore them. If there is no lpq.exe in system32 than that applications is no installed and does not need a .mui file.
If it get's installed (by dism) later, it should copy the .mui, too.
MinWin and RAM booting Windows was a - just for fun - project for me.
I don't share your passion about it. So if you want to create a database, be the first one adding something to it.
For me, I only provide the tool and a basic example.
Oh, wanted to improve that error message for years.
You have a WinPE selected as source, that's not supported and doesn't make sense.
Use bootice to create a boot entry for the WIM file.
No, Setup=1 just means the filter is only used for sources that are still setup mode (SystemSetupInProgress=1).
With some luck you can get the missing file logged somewhere in \Windows\Panther.