What is the max height, width & depth the custom cabinets can be? (We do not advertise this)

-Tall cabinet max height is 82", w/legs 86" -Max depth is 30" -Max width is 36"

How is the countertop backsplash attached?

It is attached to the wall with construction glue. (not provided)

What to do if the cabinet shelves are loose and come out of the shelf pins?

A good solution to this that will help are door bumper stickers. (read more)