Unusable Private Key

i managed to import my private key and some public key for my friends. But the key-pair including the private one is only visible in Kleopatra not in GPA. An in Kleopatra i can not change the Passphrase not the date “valid until…” . When I trie to send a Mail via Kleopatra the Key is not in my recipients list.

What am I doing wrong here. GPG is not usable this way.

Regards, mExx