Anyhow OS is Tahoe 26.6.1 and I used the "Library folder" as a test.
Under "Group" I used "Admin" and ticked R W X, Clear ALCs and"Apply to enclosed" under folders.
Using a utility to batch change permissions was a horrible suggestion, if you don't want you're changing you should not touch it. Its also been 10 years since the last update.
No, it depends on what files and folder do you select. Keep your eyes open!
Do not alter your home folder and or system related files!
Do alter those files and folders who copied from disk or you haved changed permissions so much that nothing works.
My cousin gaved me a DVD back then about Apple related stuff. Copied to desktop it was impossible to alter the view options because of faulty permissions. Use BatChmod on this specific folder everything is fine.
The proper usage of BatChmod is: only select the file or folder that will refuse to work properly! Do never ever try to do something else!