Guy P

You know you may need to add a mppt controller to that?
In which case the string setups will depend on that controller requirements.
The victron guys on the forum will be able to answer on that.

The relative area of the two metals makes a difference.  An aluminium frame (large area) with S/S nuts and bolts (small Area) will be far less of a risk than the other way around.  But as said above, coat it to keep the surfaces at the point of contact dry (i.e. no electrolyte) and it should be OK.

Note that the frequency of the generator must be relatively stable.

I just set up a Luxpower... or tried. Unless you get connectivity going to the app, you have to navigate stupid number menus similar to the Axpert menus. I am not convinced that it is worth the saving compared to Sunsynk/Deye.

If you need to install panels across two roof sections, pointing East and West, then the ideal would be to put each set of East and West-facing panels on a separate MPPT, ie. use an inverter with two MPPT inputs. This could be a Sunsynk, but there are also cheaper options like Luxpower.
The amount of panels and battery size are difficult to suggest without understanding how much energy units in kWh your house uses, and at what times of the day, and what's the highest usage of any time. Regardless of the spec sheet of any inverter or battery, the process should start and end with understanding your needs.
To get an idea of how to wire it up, best to review the installer manual for the specific inverter. In the case of the Sunsynk it's possible to wire a generator onto the AUX port of the inverter.
Seems a waste to scrap a perfectly functional inverter. Why not try passing it on to someone who is just looking for an affordable backup option.

I kill you over kilo.
That looks like an old inverter, 1 MPPT, low solar voltage, no export. I don't know how well BMS comms will work or if blending sources are possible. A Sunsynk would be 10 times better.