From user feedback and personal Experience I find the Ownertrust dialog in Kleopatra too complicated for our target audience. If someone wants to set marginal owner trust the command line should be used.
I would like to have this dialog simplified to:
Do you want to allow <Primary UserID KeyID> to mark certificates as valid (VS-NfD compliant) for you? (VS-NfD of course only in the VS-NfD Mode)
Below in Italics: "This means that you trust the owner of this key to check fingerprints and confirm the identities of others by accepting their certifications as trustworthy."
[Yes] [No]
No-> Unknown trust
Yes-> Full trust
If the Secret Key is aviailable instead:
Is <Primary UserID KeyID> your own certificate?
[Yes] [No]
Yes -> Ultimate Trust
No -> Open the Dialog for a third party certificate next (the one above).
Wording is mostly a suggestion but I think this would be enough.