Definitly yes !
Materializer is designed to allow everyone to access the power of node tree (no maths skills needed). The starter course will help you a lot.
Nodes are everywhere and in all famous softwares (Substance Designer, Gaea, World Machine, Nuke...). To avoid them is to avoid an important part of the 3D world.

2 nodes allow to make mask edges.

1. "All edges" works only with Cycles.
2. "Edges" works with Cycles and Eevee. Because this node group uses an ambiant occlusion node, activate the ambiant occlusion in the Eevee settings.
   

Yes you can. The add-on propose a certain way of building the materials, then it doesn't matter if the maps are from add-on or not.

No. It's a tool to made your own material.

No. The add-on is in the shader editor, the goal is to speed up the node tree creation.

Yes.

All Materializer's nodes are made with native Blender nodes, so the viewport speed isn't related to the add-on.

I advise to design with Cycles instead of Eevee. Use Eevee at the end. No relation with the add-on but with Blender technology itself.

Eevee is a game-like rendering engine. Eevee is designed to make image based material. It allows real time rendering but at the cost of loading time. When you are in the design phase, you will modify the content of your material a lot and each time you add or remove a node, Eevee will compile the material again. A particularly slow operation. Conversely, Cycles takes longer to render smoothly but applies the changes made in the material instantly.

To be quick : Eevee isn't designed for procedural material study, it's related to the Eevee technology.