Bricks, Masonry, Asphalt and Concrete - Flagstone on existing concrete

I have an existing concrete-aggregate patio (about 1000 sq. ft.) that I want to resurface with flagstone (random pattern). The existing patio is about 5 years old and was poured in 3 sections 7 inches thick with an expansion joint in
between the sections.

Will the concrete slabs move independently and cause cracks in the grout (or worse, the flagstone)? Is there any way to prevent this?

I'd also like to bring irrigation and wiring to a couple of locations in the middle of the patio and imagined a groove about 1" deep and 1" wide being cut in the existing concrete, pipe laid in the groove, and then mud and flagstone laid on
top. Is this realistic?

Thanks,
Steve

Wherever there is an expansion joint in the substrate, you will need one in the same place in the flagstone. If you cut additional grooves in substrate, there will have to be an expansion joint there. Each section will tend to expand and contract on its own. Thus, topping off with tile or stone will require expansion joints in the same locations.