Nigel: The problem is the definition of common sense.
I know of several "small" operators who are very successful commercially for the following reasons:
1. They comply with the letter of the law.
2. They are open and tranparent with their operation to the regulators AND the insurance underwriters. Insurance companies love endless details on operations so that they can more easliy provide an accurate quote.
3. They insure properly.
4. They do everything to protect their estate.
With regard to the last...remember this. NO insurance policy can mitigate sufficiently against statute law / common law.
That is to say that where there is serious injury, death or serious damage to property, it is up to the Coroner/law to appropriate UNLIMITED fines against the perpetrator.
My advice:
Make sure there is a sufficient buffer between you and the claimant regarding insurance cover.
If I was a small time operator like this one in the US, I would be looking at around $150 - 200,000,000 cover (because it's America where spilling a coffee over someone initiates an $80,000,000 claim!
In the UK: £50 - 100,000 for product/third party/ passenger cover.
I would put everything I own privately in my wifes name!!!
I would have a decent litigation lawyer on my books.
Risk Management and a very decent SMS is where it's att these days Nigel.
Stay safe.