Nice work. I have not noticed bigger problems apart from the language-selection with NFS4.
Indeed, changing the language will result in crash at some point. Solution: stay with default language
Really only minor issues.
Though, i would suggest you add a choice "manual" to the "TrashDriver" section, that doesn't alter the "ThrashDriver=" line in the nfs4.ini - this way it will be possible to set new drivers (like different render versions or zbag's driver) without casuing conflicts to your setupMP.
The tooltip/description of the language selection is reffering to NFS3 only but should be generalised.