Hi Count Robio
welcome to the forums.
Regarding inexpertise #1/2/5, you need to know the Eventide handles -20/-10 dB instrument level unbalanced signals on 1/4" jacks, whilst +4 dB balanced/unbalanced line levels signals are only handled by XLR I/Os. I assume your preamps output a 0 dB or +4 dB line level signal, unless they have a selector to reduce it to nstrument level (which is not recommended anyway!!!). You should use XLRs connectors on the Eventide, with balanced cables, unbalancing the cable ends connected to unbalanced gear. The manual explains this.
It was our plan to provide an User Presets exchange area but we haven't been able to make it happen yet, owing to a number of different reasons, including some high priority tasks. Hopefully it will happen soon.
enjoy your Harmonizer