Something to aspire to Ross, define suitable breakers, what current?
In this case, my panels have a Isc of 6.2A, and running 6 in series has a nominal Voc of 132V.
And as a reminder series is the same current as a single panel just adds the volts.
Absolutely. (Until you then parallel series connected modules, then you start adding amps again!)
I am not sure that two pole is necessary although would not hurt for DC in this application, definitely for AC 240v application switch only the active.
Like I said above - check your local code.
In order to comply *HERE* they need to be double pole. While I'm not grid-connected, and never likely to be, I adopted:
* Safest practice, wherever legal
* Best practice wherever possible
* Code compliant where practical as long as it was consistent with the previous two points
Edit: Found one of my old working block diagrams....