this depends on how and what you want to patch. for a “classic” flute or wind instrument patch you have a sustained excitation, eg the noise you put into the delay/filter feedback is constant.
if you don’t want the exciter signal to be constant you can put the d0 into selfoscillation, so it has a constant tone, shape that tone with filter etc and control it’s envelope with a vca inside or outside the feedback path.
depending on what you put into your feedback path you need to adjust the feedback/gain knob, if your filter/waveshaper/freq shifter etc has a gain control too you have to decide which gain you put as “master feedback” control. also with filters…as soon as resonance is introduced the feedback can indeed get out of control quickly, resonance is nothing else than a feedback for the filter so this can blow up if you’re not careful. again, patience and small knob movements 
if you set the slew to high noise can be heard. set it to the point where the noise disappears. again, the cv inputs carry gain, this also can have a noisy effect if not zeroed out. and then obviously the power can have an effect on noise, you really need a stable +5v for the d0.
that’s normal, it is not an oscillator but a delay, and positive voltage changes the delay time down (think knob movement to the right, the delay gets longer, so for ks patches that means the pitch gets lower. that’s why the attenuverter are so handy, just invert the cv. the tuning to exact 1v/oct takes time and is really not fun, it is perfectly possible, believe me, the scaling is v/oct, it’s just alot of work.