I'm glad you asked this - as an aspiring CEO myself someday, this is a fun "what if" game.
If I were RS's CEO I'd focus on 3 major areas for the core business:
Accessories: Whether it's a cable, connector, battery, antenna, charger, remote control or carrying case we would stock it in every store.
Service: The other side of the coin that is the core business. I've got a tablet right now that needs a new screen.
Consumables: Printer ink, toner, paper, blank DVD's, batteries, we'd have them all right there in the store, clearly marked and easy to find. Pricing wouldn't be the cheapest out there, but I think RS would win by selling the convenience of already being in the store. I'd also have a kiosk in each store that can help you pick the right cartridge for your printer or the right battery for your cell phone - another convenience. It could even give you a coupon towards a future purchase.
Other things:
I'd lose the "assault you at the door" salesdroid behavior. That's a turn off and keeps people from wandering in to look.
Radio Control toys should be prominently displayed up front and visible to passersby. Take advantage of kid's natural tendency to want to see the cool dune buggy or helicopter, and their parents will follow.
Create a loyalty program. Each purchase earns you points towards stuff you might actually want to use, such as free batteries or printer ink or save them up to redeem for high end electronics in the online store - something to keep you coming back and thinking RadioShack instead of Best Buy or Walmart when you need some batteries or an HDMI cable.
-AZ