I'm glad you asked!
From reading your other post, you are doing the right thing. Taking that NRA class will help you decide what you need for protection.
A cared-for revolver will very rarely malfunction. It is possible, but not likely.
Limp-wristing can cause a semi-auto to malfunction. I do not understand the "full tilt of rapid fire" statement. You do not have to shoot rapid fire to use a semi-auto. In fact, most people can't shoot fast and accurately (at the same time).
Welcome!