Using classic Outlook for Windows in business environments
Can appreciate you marking my response as not addressing your question but can only provide the information to the question asked and clearly showed how it was possible to not receive a "read receipt".
Regarding "Delivery Confirmations" that depends on the recipient server. Like "read receipts", there is nothing you can do to control what happens on the recipient side of things. You can ask for the receipts but there is no guarantee you will receive one as was explicitly described in the Tracking section shown in the provided screenshot.
As for your 3rd question, would be helpful to know what "bit of help" you are referring to and what version of Outlook you are referring to?