You do not need an inverter generator, they are very nice and put out very clean power but people have been running RVs on non-inverter generators for years. Most generators that come built into RVs are NOT inverter types; this is likely to save cost to the consumer.
The generator you have will not "cook circuit boards" if it's operating properly. If the voltage is within spec. and fairly well regulated there shouldn't be a problem. I don't know how well regulated that unit is, a surge guard would probably be a good investment for anyone who has lots of electronics in their RV, especially if they have a generator.