Sharing report/dashboard

AlimahS 

Is it possible to pin a widget (consequently report) shared from another user to my dashboard?

 Yes. You can create a dashboard tile and in the properties set the custom link to the report URL of the report shared with you.

Is it possible to extract a link from a report shared with me - input into my report allowing those who I share my dashboard with to access it?

If you can access the report link because it is shared with you, then it will resolve when you click on the link. It does not mean, that it will automatically work for others. The same report needs to have been shared with them as well, otherwise it will throw an error.