Remove the email from the Work email field and put in the Personal email field. Also the primary email address shows Personal in the drop down list field. So in the name fields you'd have Joe, Primary email address = Personal, address only in the Personal email field.
Hmm...there isn't an entry in the Work field, just in the Personal one. However, if I put the address in the Work instead of Personal field, it sort of works and the email address isn't shown. I still can't just get the first name showing, though, unless I leave out the surname. And as I have seven people called Pete or Peter, I'd have to be very careful, as one of them is my other half!
It looks as if I'll have to give up on this one. I'll leave it unticked for a couple of days in case inspiration strikes.
Ok I've been playing about a bit. Have first name and surname in the fields. Email as personal and in the personal field with work field empty. Typed a nickname in the nickname field and saved. Now it just shows the nickname when I click to send email. When composing a mail I click on the 'to...' at the top. The list opens for my contacts and it shows the email on the right so you shouldn't be able to send to the wrong 'Peter'. :)