Please find inline the answers to your questions -
1. When an opportunity is being tracked in CRM How can you find out the owner of the person who tracked the opportunity?
--> There is no option to find out the name of the person who tracked and set regarding the email to an Opportunity.
2. When the owner of the tracked email tracks the email to the opportunity it will show as 'Tracked to Dynamics' will the recipients he sends this tracked email to see the email as being tracked to Dynamics too in their outlook? will everyone who has been sent this email see in their own outlook 'tracked to dynamics'?
--> When the tracked email is sent, it is considered as a new email and that will not show as tracked to Dynamics unless the sent email is tracked to Dynamics.
Only if the recipients are contacts of the same CRM organization and if they have App for Outlook setup successfully, they will be able to see that the email is tracked to Dynamics.
If the sent email is not tracked to Dynamics, then the recipients even if they are contacts or any entity record in the same organization will not see the email in Dynamics.