Is there any way to check if a script (script1) is finished executing (i.e., Can be added to debris) from another script (script2) without a modification to script1?
You would have to add a Global Variable when Script1 is finished, you change that Variable to "finished" and then have Script2 start when that variable = finished OR you can have when Script1 is finished it will change a Variable. And if you want a script to be removed just have a wait(1) at the end of the script and then make the scripts parent Debris