It doesn’t matter how careful you are. At some point of another, a plugin is going to cause your WordPress website to crash. The only way to avoid a crash is to have a test area that is an exact clone of your live website; with the same plugins, posts, pages and theme. Whilst I am a strong advocate of actively using a test area to try out new plugins and changes, I do not believe it is practical to keep an exact duplicate of your live website, particularly if that website has a lot of content. So realistically, you’re going to have to deal with a problematic plugin in the future.