For number 5. It's actually not about functioning correctly. It's about 2 things. One is that newer versions will always have new features that do cool things for you and will be faster. Like a newer version of DOSBox or ScummVM, as an example might play games with better performance and FPS than an outdated one. Two, and this is the most important one, when you leave any program out of date, no matter what it is, you put people's PC's at risk with potential security holes that can open up gateways, and back doors to malware, viruses, and hacks etc. Any program you have on your PC, regardless of whether it is installed, or a Zip file/Stand Alone/Portable MUST be kept up to date at all times to ensure that all vulnerabilities are patched out, or else get rid of it/don't install or download it.