Several questions
 

1) First off how important is it to use the "-engine ep1"? Hammer gives a warning, "The configuration information for the game you're trying to edit is invalid or missing," when I do this and it becomes unstable for me (ex: if I try to load a prop Hammer just crashes/closes), but it appears everything for FF works just fine if I leave that off and follow the rest of the stuff.

2) Secondly, I just started playing around with a map, but I was using regular HL2 textures and a static prop, but it appears that when I try the FF configuration some of the textures I have used and that static prop (just a tree) they do not load. I do see a decent set of FF textures available, but they don't appear to share the HL2 general textures. I thought that HL2 Ep1 and HL2 textures were available to all mods, I guess I misunderstood, I accidentally used an EP2 texture or something related to issue #1. Is there a standard way to convert maps to FF or is that just replacing the props and textures?

3) I have great trouble running these maps under FF, but I can at least run around and explore the lighting, etc. by just pretending its a regular HL2 map. I followed the guide, but even the "-appplaunch 215" appears to have no effect.

This is because you have not played a certain game since you have installed it. Maybe hl2:dm, hl2, hl2:ep1.. I dunno