Users do not need the ability to modify scripts, just the rights to execute them.
What kind of error message do you get when you click the buttons?
i have 2 buttons < & > bro ! And With My New User i can't Click On it
There is nothing in the security schema that prevents users from clicking on buttons so it is not clear to me what error you are seeing.
- do you have a hide condition on the buttons?
- or can the users click on the button but nothing happens?
- or can the users click on it and an error dialog is shown?
Either way, if you log in with a test account that has the same priv set as the users and then use the Script Debugger it should become clear immediately what is going on.