But don't forget the configuration of those softwares...
Some need files in /etc, some in your /home, some /elsewhere...

Your Email client is an exemple. It may generate a random name directory to
store stuff. Ensure you can keep your stuff

At least keep a good backup of /etc and /home.
And you should have a logbook of all actions that you did on your machine in
case you need to reinstall. Often you cannot just bring back the old
configuration if you use a newer one... Some thinking will be needed.