re: Getting Rid of Control 4 - Recommendations?

It sounds like a Sonos system could be perfect for what you are wanting to do (except for keeping your existing receiver). If you want to do three zones and keep your existing wired speakers, you would need to buy three Sonos Amps (one Amp for each zone). Each Sonos Amp currently costs $699. This would definitely meet your criteria of “fairly simple with a nice mobile app” and “user friendly.” I doubt you would need to hire a company to install it for you, but I’m sure you could find someone to hire if you really wanted to.