@ricksrod, sorry for the delay, I didn’t see your questions til just now.
1. They sent an email (this went to my updates folder in Gmail, so I was lucky to spot it). This never appeared in the online ‘track your application’ tool.
2. The original guarantor was accepted as a civil servant not related by marriage, despite being a domestic partner to a relative. In the subsequent letter the passport office said that they now thought that the guarantor probably was related to us after all… not such a surprise, I had been a little shocked that they would discount domestic partnerships!
3. We were directed to send everything to Durham.