Suggestions for Digital and Analog Connections?

USB vs Coax... Depends. Cable sensitive too.

You are advised to try whatever you can.

Start with cheap cables on both so you can A-B.

I did that on one setup and coax wire does way better SQ than Toslink glass. USB about tween.

I would recommend using an iFi SPDIF iPurifier with a coax connection before the coax input of your DAC.

As for brand of cables my personal preference would be Mapleshade

My budget preference would be Pangea.

I did the comparison when I had an Auralic Aries G1 streamer between USB and AES/EBU and the USB sounded better. The cables were Audience AU24SE+ USB and Fadel AES/EBU. Definitely not apples to apples but take it for what it’s worth. 

USB gets bashed a lot by those selling competing products. A lot of work has gone into audiophile USB. A lot of $100K systems use USB. I am very happy with it (in my <$100k system). I did spend $200 on a nice USB cable from my Innous Zenith MK3 streamer to my Dave DAC.

Lots of good RCA cables out there. Audio Envy is an affordable one. I build my own with KLEI connectors and mundorf wire braided.

I don't know Apple but I assume the mini will be your Roon Core?  I recommend installing ROCK, always stable.  

Jerry