Is FUE restoration for receding sideburns possible? (Photo)

Yes, a well-trained and experienced hair restoration surgeon should be able to achieve very natural looking temporal tufts and sideburn areas. Many people avoid this area because it uses up a large number of grafts that might be useful elsewhere, but it is possible to treat the sideburn and temporal tuft area with hair transplants.All the best,

You can have hairs transplanted to your sideburns.Photos cannot determine if you would be a good candidate for surgery.  You need an examination and the doctor needs to understand your goals and expectations.
You need to have good communication with your doctor to understand what your end result will look like.

It is definitely possible to restore the areas of concern displayed in this photo.  You should meet with your hair transplant Doctor to come up with a plan of action for you based off of your donor density now that it has already been harvested once.  You should be okay to fit those areas after only one FUE surgery.  

The answer to all of your questions in my opinion is "yes"; provide the physician performing the procedure is knowledgeable and has an artistic eye and a well-trained staff.

This is the nature of of hair loss : it's progressive and non-stop. Go back to your surgeon and inquire about additional FUE treatment for this and other thinning areas. Likely, you've been told that multiple procedures would be needed, especially if you are young and are not taking finasteride or using Rogaine or laser therapy, etc. Good luck to you. 

Yes, this is easy to do provided that you are not balding and understand exactly where you might end up balding in the future. Best if you are over 26 years or age.