Right on both screen and lights. And yes, check your parts. I too was missing a wiring harness. I've been using the shorter screen in the heat of summer and will switch back to the tall screen in cooler weather. At 6'2" I get some buffeting from the short screen but will take that for more airflow in the heat. The tall screen provides excellent protection.
GPS and radar detector are both Ram mounts. I had them on my R1200GS and just moved them over to the R3T. Triumph sells a wiring kit for the GPS. It doesn't match a Garmin plug so instead of splicing the Garmin wiring, I used the GPS wiring harness to power my radar detector and ran the GPS power plug to the accessory socket (another optional part) that mounts just below the seat/tank on the left side.