Welcome to the Campus.
There is no reason to remove older versions unless you need the space. They don’t interfere with each other. Sometimes, older versions might feel more comfortable, or sometimes, newer versions might misbehave or have bugs that you can circumvent by using another version. I have all the versions, from 8 to X9 installed on my computer. However, if you want to remove the older ones for space issues, make sure you copy all the resources includes in them and save them somewhere safe. You can always use those supplies in other versions.
Here is a blog post about those resources: http://scrapbookcampus.com/2014/10/using-resources-from-your-older-paintshop-pro/
And by the way, my husband is a Barclay too, but i am from Canada! Probably no relation 🙂