Questions on AddSpell usage

[Halstrom]

If I use :

player.AddSpell DrugPlayerEFFECT

inside a continual running quest script to trigger the Effect do I need to use RemoveSpell to stop it or would it stop when the Base Effects time out.

The DrugPlayerEFFECT contains:

Reduce Strength for 2 hours Base Effect

and also a

Base Effect containing a Script that triggers modifies some values in the main script once. Or am I better just adding ths script to the DrugPlayerEFFECT directly?

After reading the Wiki I'm pretty confused on what the Script effect option does with it's duration setting, and the checkbox for "Script Effect Always Applies"

Of course I could do most of this in the main script directly but I'm trying to make it modular for other options/expansion later and more friendly for lesser experienced people to mod values.

Thanks for your time