Hi,
Try to reuse Mic Volume in Audio Settings. Also If you have "+20db" amplifying, you should disable it in Mic settings.
To reduce hiss, use high-pass filter(effect)
Works excellent for me! No pixellising here when building slideshow.
You can see pixellising only at Preview time. We use this to render effects in Real-Time.
Vec USB foot pedal works fine for me.
Which one you using?
Aslo tell me do you running other foot-pedal software, eg Pedable or ExpressDictate when you found this problem?