In 1, every output would be digital either via USB, optical or coax...
Don't see any benefit to that. If you were using a digital processor with useful features like bass management or system optimization implemented digitally, then there would be some obvious advantages. As things sit, you're just buying two DACs for every one that you absolutely need.
Turntable into Parasound ZPhonoUSB into Emotiva XDA2 DAC via USB cable into the amp
I hate to echo the masses, but this has me scratching my head as well
Unless you plan on using the phono pre's USB out to transfer to your PC/make digital copies, just use the analog out on the pre.... or any other phono pre you may choose.
Also, without trying starting a huge debate here, I thought the point of a higher-end phono pre is to "preserve" the TT's analog signal. Going to digital back to analog would (probably?) void out any benefits/sound quality from your phono amp.