GSE is not AHK. GSE is a macro compiler. It is entirely self contained within WoW’s API. You don’t need to use AHK with GSE. You can use GSE totally on its own.
AHK, GHub, Synapse etc are THIRD PARTY tools not using Blizzard’s approved API to automate keystrokes. ANY use of these tools with WoW can get you banned. You can use these tools irrespective of if you use GSE or not - they are not required for GSE.
With relation to these tools there are two concerns: boting and unfair advantage. AHK can be used to write a autoplay bot for WoW not just for automating key strokes. The unfair advantage is from using a third party tool to achieve what an average person could not hence the recommendation to not go below 250ms.
In response to “But my macro runs crap at 250ms”. Let me fix that. Your macro is crap write a better one.
The full version of this post is located at Guide: macros, WoW, you and more - #55 by TimothyLuke