I see from the old character files that there are taunt animations. I have yet to see anyone using them. Whats up with that??

Actually I think Dresk uses them on his mod.

Yes there are taunt animations but that does not seem very useful to me.. Dresk uses them in his mod when you are 'unavailable' like chatting or have the console open so people can more easily see you are not a thread to them.
Also i never tested if every model has a taunting animation but i think so. Still i'm not sure its a useful thing. Almost noone will see/use them imo.

Would there be any way of calling up these animations in normal Nexuiz [not while playing the Spidflisk mod] ?

No, unless you see 'change some nexuiz code' as a legit way

Thank you for the information.