This is the first time I'm using the ATmega32u4 in a design. I've been looking at a few reference designs and I think I have everything correct, but I wanted to check here and make sure there's nothing egregiously wrong with the crystal/supply/USB portions of the design.
This board is basically an alarm for a pressure sensor with some buttons and a display to set the alarm conditions.
I included an ISP header just in case, but I want to be able to program this board via USB as an Arduino Leonardo using fresh ATmega32u4s from Digikey. My understanding is that I want the non-RC version as they come with Microchip's preprogrammed bootloader. In this case I should have an external 16MHz clock, right?