4.2 LTS and newer; tested on 4.2.23, 4.5.14 and 5.2.1 with identical vertex, face and triangle counts (134 cases each).

Standard shader nodes (glass uses transmission, neon uses emission), but only Cycles was checked.

No. Both are optional and sold separately. The shop front stands on its own (it has its own piers and fascia). With Altbau Facade, put the Ground Floor Cutter into a Boolean; with Windows & Doors, set Door Type = Open Frame and use the door outputs (README has the steps; gallery images 10 and 11).

Inter, Oswald, Playfair Display, Pacifico, Bebas Neue and Alfa Slab One, all under the SIL Open Font License, which allows commercial use including text turned into geometry. The licenses are in FONT-LICENSES.txt.

The Font input picks one of the six packed fonts. To use another font, open the node group and exchange the font in the String to Curves nodes.

Yes: every material is an input socket.

No; apply the modifier and decimate. A shop front with 3 axes is about 5,943 triangles realized; a sign between about 3,000 and 35,000 depending on type and text.

Yes, in any number of projects. You may not resell or redistribute the asset itself. Personal = one person, Studio = one company up to 10 people.