I tend to disagree. The fingerprint is a very long and cryptic looking thing. Most users of Kleopatra will never share their fingerprint as they tend to work on a TOFU model, just accepting a given key and using it. For another bunch of users the long keyid, which we show, is more then enough security. And for the VS-NfD case with very high security where users compare a full fingerprint it is accessibile enough.

So while showing the fingerprint would be a slight improvement (over the keyid) from a security standpoint I think that it would lead to more users feeling overwhelemed by cryptic stuff. And it makes it much harder for us to layout a decently sized table in the default window size.

Regarding the right click, I think the certificate details are the best place for it, which can be accessed through rightclick. In the next version we will also have a button next to the fingerprint in certificate details to copy it directly to the clipboard which makes sharing easier. So we have an improvement there which is also a reason why I tend to go for a Wontfix here.

Sorry to use Wontfix for your first UX suggestion but Kleopatra is always weighing Security VS. Usability because if users feel overwhelemed by the software they will close it and never use it and thus overall security is lessend.