Is it possible to have one variable that is accsesible through other many different . as files? if not is it possible for me to put a variable inside its own .as and have the others call it?
Unfortunately the straightforward _global of AS2 is no longer. I believe your best bet is to create a new class with a static variable. That way if you import the class, you can access that variable globally.
//as3 package { public class Global { public static var vars:Object = {}; } }
Then you could import the Global wherever you want to read or write the variables.
import Global
From there you can write your variables and access them anywhere you have imported the package.
Global.vars.myNewVar = 1
Anywhere Global is accessible, Global.vars.myNewVar can now be read and used.
What WhiskeyesJack said. Also you don't have to import it to access variables in other classes, you can access static variables anywhere just fine using the <class>.<static_var/cons>.