LFO, AR-gen, filter questions

[kobresia]

So I finally finished stage one of my SoundLab, basic unit fed by +/-12V mains power (works fine). Still to do - finish front panel, oscillator cross modulation (isn't this technically FM?), ring mod, 8 step sequencer + various small mods. By the way 2N3819 JFETs (in place of MPF102s) for oscs also works fine, but pinning is different.

I've also built an extra LFO, but I don't have a 2uF capacitor (C13) at hand, the one to be mounted behind the panel. I used a 1uF for the first one, which seems to work fine, frequencies get more than low enough for low range (at least 5 minutes peak-to-peak).

So my questions are:
What would a lower value capacitor C13 do for the frequency range? You'd get a higher minimum frequency for low range right?

Why is AR and especially LFO mod depth not-so-deep for filter, pulse width, VCA? How would I go about increasing it? This means AR can't actually sweep the filter all the way (but fairly near), and LFO just sort of wobbles it a bit (but sweeps oscs several octaves).

Why is there an added "floor" voltage for both LFO and AR-Gen mod? When I switch LFO mod for filter on, cutoff increases quite a lot. When I switch AR mod for filter on, cutoff increases slightly.

Filter really squeals heavily on highest resonance, is this something you all get too? It's kind of nasty, but kind of cool too, so not really a big problem.

[etaoin]

[kobresia]

[Pehr]