Waitforchild in global scripts (is it needed at some point in global scripts) ?

Not really. And they're not global scripts. They are just "Scripts" or "server scripts"

they are unneccesary, but they are used in every script (for ex. if your doing "playeradded" and your adding a bodymover to the torso, it will give an error because character isnt loaded yet so you have to use waitforchild in that case.)

Well obviously I'll use character added after that though

You can't do player:WaitForChild("Character") and expect it to wait for the character.

Character added I mean the function

Player.CharacterAdded isn't a function

You get what I mean