It depends on what type of scripting you are referring to.
If the script performs certain actions for you (aiming skillshots, dodging skillshots, etc), then no. No it is not.
If you are simply rebinding your keyboard buttons to your mouse or gamepad and are still performing all of your actions by yourself, I don't see any issues with it.
If it helps, I have seen computer accessories which include the mouse and many buttons set up so that everything may be accessible using one hand. The buttons are bindable and you could easily set them up to use items and abilities in the game.
Unfortunately, I forget what they are called.
This is unrelated to the above, but you could probably get away with a gaming mouse such as this with some practice.