Can i delete stringtable.xml files? and other files i can't delete?

Im clearing space on my computer, i don't really trust apps, they haven't helped me much in the past either. Plus i want to look at majority of the stuff before i delete it. I'll use an app if its good afterward for all the things i rather not search through first. Is it safe to delete stringtable.xml files? They were from my messages. If possible could anyone list me the specific files to NOT DELETE! And afterward reliable apps to delete things like caches.