Also, I think his note about all the .wad files is wrong - from memory, you list all the .wad files you want to use in Hammer's configuration menu somewhere and

Also, I think his note about all the .wad files is wrong - from memory, you list all the .wad files you want to use in Hammer's configuration menu somewhere and that entire list gets inserted into every map you make, regardless of whether you use it or not.