Sorry it's taken so long to get back to you, i've been crazy busy here.
Source is very picky about what format of WAV it will play. Did you try the boltgun sounds as MP3s?
I tested the footsteps in-game. It sounds like walking around with cardboard boxes on his feet.
I listened to the marine vox stuff, i'm not sure about them at all. Maybe pitch shifting them down a bit will make them sound more "mariney"?
FYI the effects for the marine voices we have so far are done in Audacity, using the "delay" effect. decay amt 1.0,
delay time 0.03 and all the rest of the settings as default.
The effects i've used in the voices:
Goldwave - Slight Flanger effect
Audacity - Same setup you've got except i have them on 5 # of echos
They sound strange because they're just death screams, the voice effect that you told me would be more effective on normal voice acting, not a person screaming into a mic, heh. Sadly i don't have any equipment for voice acting.
Also thanks for the feedback