going off grid > electrical

[writejill]

We have purchased a bus conversion. The current set up requires the bus be plugged in to run any outlets, with a few (water pump & one set of lights) on DC.
There is a converter with AC and DC panel, battery bank, and power plug. The house batteries are not connected to the engine's alternator. Should they be?

Is it better to replace the converter with an inverter/charger, which would mean installing an AC and DC panel?
OR
Is it okay to just install an inverter for the AC outlets?

Is there concern that a converter does not properly charge house batteries? If going the plan to just add an inverter, should I consider getting a multi-stage battery charger?
Do I need to choose a pure sine inverter?
In an effort to live off grid, we will use a generator to charge the batteries as needed.

Should we also add a surge protector?

Thanks