I am going to write a onTouched function and make it change some values located under it when it's touched. Would it work just fine?
The simplest way to decide is to fist know:-
Thing that need to be local scripts
Thing that need to be a script
In short if its doable on the client side for effects and does not need to be transferred to all players or secure the make it a local script.
I do not know your game design so we cannot answer for you.
Feel free to add to this or make changes, just post a comment and I will add it in.