I can't help you with the pocket screw question, but I would caution against it. The particle board it's made from is not strong and will split easily. I drove some drywall screws into some pre-drilled pilot holes this weekend, white 1/2" Melamine and they split out in the edges, separating the two surfaces.
For the kitchen I made about 20 years ago, I made dados and rabbets for all the 90 degree joints and used Liquid Nails adhesive for the "glue". It sets up quite hard and bonds to the Melamine. It is a pain to work with and will stick to everything, especially your fingers. Wear Gloves.
The Melamine kitchen was not perfect, but was "temporary" for about 15 years, until I could afford the real Mission style Hickory cabinets which I ordered ready made. It's been a long while, but I think there was around 13 K in cabinets for all 3 rooms, kitchen, dining area and family room. The commercial ones aren't perfect either, but quite a ways above the Melamine version I built.
Melamine is very sharp and will cut you up when working with it. Wear non-slip rubber gloves when handling it. I don't envy you working with it.