Are ancestry, find a grave, etc linked to family search? Is there free access to any of these other than family search?
I am not totally clear on your question but I think you are asking if FamilySearch and Ancestry talk to each other. That answer is no but Ancestry is a partner of FamilySearch. You can access Ancestry records through your own personal paid Ancestry account or you can go to the nearest Family History Center and access the records from Ancestry for free there. To Find the nearest Family History Center Click on this link:
You can enter your address and discover the nearest Family History Center or Affiliated Library. The address and hours of that location will be available and you can go there to get free assistance.
Regarding Findagrave quite often you will find a Findagrave hint under the research hints on your ancestors person page under the Research Help on the right column. Often the Findagrave has already been attached and will show in the sources for that Ancestor.
Hopefully that will answer your question.
Thank you for contacting FamilySearch. It has been a pleasure helping you. Best wishes as you continue finding records for your family.