The STL files are only intended for personal use.
All the models vary in size, but the largest will fit within a 200mm x 200mm FDM printer build volume
No, all the files are designed to be printed without supports.
Feel free to modify and share the modified files to friends and groups but please do not sell the files. Please do not offer the files on sharing sites such as Thingiverse or CGTrader.
Don't see the answer to your question? Ask the project creator directly.