I’ve got 5U not euro, but I think +5v is fine.
Yes lin value of CV A&C should be at zero so whatever your sending it to is closed unless the envelope is triggered. Zero as well for LFOs unless you’re wanting to offset it for some reason.

In terms of P-locking you might find more interesting dynamic results from modulating the envelope destination depth or ADSR settings, as opposed to the CV lin value.

Think about it as the lin value on the CV channel as the baseline of your envelope and the destination depth on the env sets the peak. For LFOs your lin value should be the zero point and the destination depth will control the amplitude either side.

Hope that helps/makes sense.