if any of that can be done it most likely would be with jack (jack audio connection kit) and ladspa (linux audio developer standard plugin aritechture) plugins.
jack is a low latency pro audio quality audio subsystem that runs on alsa drivers.
ladspa plugins are dsp effects and post processing for audio signals, i haven't worked with ladspa that much though, so i can't give firsthand on them.
with jack though you can route your audio out from one program to audio in on another, so if you have a program that does the effects you want you can just wire them into each other. you might want to look at pure data for some really low level audio stuff, its got a little bit of a learning curve to it though.