A catch can may or may not help with intake valve coking, but it will not jeopardize your warranty. Whether a catch can is useful depends on the amount of crankcase vapor carry through on your particular engine, the design of the catch can and the proper installation of the catch can.
Top Tier will do nothing for intake valve coking, as the fuel and therefore the detergents in the fuel, never touch the intake valves on a DI motor.
Using 87 vs 93 will do nothing for intake valve coking. Octane level has nothing to do with coking or carbon build up.
"Italian Tune-Up" will do nothing for intake valve coking, nor will it be of any other benefit. These aren't carbureted, oil consuming engines from 1960.
The owner's manual in Ecoboosts recommends 93 for best performance, if you bothered to read it. The 2.0 drives like a different car on 93.