I've seen a couple posts on it, but no definate answer from what I've seen anyway so I figured I would ask.

What is the decision on using textures from another game that not a Valve product? I have a map that I am using maybe 8 out of the 60 textures from another game. Is that a no no and should I replace them?

I'm graphically impaired and can't do my own and using the same textures as other maps seems kind of boring.

basically you can do whatever you want as long as youre not making money off your work. but texture ripping is frowned upon and is not accepted by the mapping community at all! So you have two possibilities:

1) go with the textures that are available (every 1.0 map came with its own wad),or chose one of the other WADs that are out: zillafinal,xerent,kamiplatinum,classic kleineh to name a few. you can find download links in the mapping faq

2) learn to texture and do it yourself.

actually you have three possibilities:

3) get someone else to do it for you (unlikely)