When I first went to America back in the 70s, everyone had to get a visa in order to be allowed entry into the Country. They considerably relaxed their previous requirements when they introduced the VWP for UK nationals and a number of other countries. As part of this relaxation, so that the majority don't have to get a visa, they require that anyone who has been arrested etc. declare this and obtain a visa. I've never heard of anyone in your family members' situation who has been refused this visa. It is still very easy for the vast majority of people to enter America. I've also never been aware of the "guns" or "faces like thunder" either and I've travelled via majority of the Eastern seaboard ports of entry!! They do take entry into their country seriously, particularly since 9/11, but majority of immigration personnel have a smile for visitors and are helpful if you need help.

I'm also not sure how someone can be arrested, appear before a court, be given a suspended sentence, and yet not consider this to be a criminal record. Surely you have to be guilty of something to get a suspended sentence?