To be on the safe side, create a complete disk image of the system before starting.
Then delete what you want, test all your apps (and what happens if you want to remove & reinstall) and then decide if you want to restore your image or stay as you are.
When I want to do that sort of testing, I usually acquire an additional disk of the appropriate size and type, take the disk image, swap the disks over and put the old image on the new disk, thus leaving the original disk untouched.
Belt, braces, chewing gum and baling wire!
SD