The Screws for the vinyl hangers is Sku # 769-295.
The gutter is attached to the fascia board which is typically recessed from the roofline of the shingles. Also we sell what is called a gutter apron which the angle of the edge is not 90 degrees which will divert water further out.
I can not find any picture showing me what you are talking about. The item you selected to ask a question on is a Vinyl Gutter. I looked at our online pictures of the inside corner and it does not show any vertical pieces.
Yes you can with no problems at all.
No this item is only available in 10'
Right there on the product page https://www.homedepot.com/p/Amerimax-Home-Products-5-in-x-10-ft-White-Traditional-Vinyl-Gutter-M0573/100079740 Click on the video on the left There is also a link to Assembly / Instructions: https://images.homedepot-static.com/catalog/pdfImages/29/298efeac-47c5-426a-bc28-6f7a9ecfe308.pdf
You would need to shim out the fascia board in this particular application. The shim would go behind the gutter. We also sell a Fascia Fixer which would also work in this application. Our Part # is T0539.
The vinyl gutter is only available in 10' Lengths. Our metal gutter is available in 10' and in some stores they carry 16'.
The vinyl gutter has its own specific connectors, drops, and end caps. The connectors and end caps have gaskets on them so you do not use caulking.
It can be recycled with plastic products.