• Super User's public is, by FAQ:

Super User is for computer enthusiasts and power users.

The "and" includes both. Regular computer users, and power users. Doesn't mean you can't ask simple questions when you have such description, in my opinion.

• Super User's scope is:

If you have a question about …

• computer hardware
• computer software

and it is not about …

• videogames or consoles
• websites or web services like Facebook, Twitter, and WordPress
• electronic devices, media players, cell phones or smart phones, except insofar as they interface with your computer
• a shopping or buying recommendation

It's probably the most specific of all sites, so far (not that this is an especially good thing). What do you suggest to improve it?

About gray areas, usually, this is a "case by case" evaluation. Some scripting questions can be answered on SU, some on SO, some on SF. It depends on what the user wants to do with them, but in general, I don't see an issue with them. Such grey area doesn't mean we have to have a clear limit, they can exist on all sites.