If you can, please join rather to chat, so I will be able to provide you quicker feedback about the sounds.
EDIT: Well, if it is not possible, so I will try to answer your questions shortly here.
unixfreak {l Wrote}:What volume do you think should be adjusted? I made more use of the radius property using no-pan as you suggested, and it seems to be more effective.
A lot volumes. I can't answer what volume you should use and where, because it depends on map elements (if there are walls or if it is open area), on type of the sound and that is variable and also depends on personal taste. And most sounds you chose doesn't fit, so at first it would have to be changed, then I could answer this.
unixfreak {l Wrote}:By the way, i have changed the settings in the options for master volume and sfx etc... what are the default settings for in-game volumes? Just wondering if the ambient sounds are audible with defaults.
You mean in options? You should keep default setting, which is 255 for "master" and 255 for "sfx" and then add some sound entities. For instance those ambient sounds are way too much audible with setting you used. That is one of the mistakes.
Example 1.:
Chamber -> Usually is used ambient sound with lower volume, because it just complete atmosphere, it's not a case of loud machine or such.
Example 2.:
Opened area, roof of building high above, very cloudy weather -> You could hear a stronger wind blowing around your ears, maybe even a stormbolt in afar (lower volume)
Example 3.:
Factory in use (inside)-> You could hear lots of sounds from different locations, some loud, some quiet, which makes mix of those sound, so typical atmosphere for factory.
Your map is a different case and describing all details would be more than just for one forum post. Hope it helped to understand a bit more of this sound chapter at least.