I'm thinking about getting a 7-port one from amazon for $18.99. I know it's a bit more expensive, but it can be used as a charger or a hub.
http://www.amazon.com/gp/product/B00DQFGJR4/ref=ox_sc_sfl_title_2?ie=UTF8&psc=1&smid=ATVPDKIKX0DER
got a link? i cant find it
So the only thing that would really benefit from the speedy USB 3 connection is the external drive. Would plugging that directly into the back of the Mini still cause the interference? I don’t deal with a lot of huge files. It’s really for storage and Time Machine back up.
Looks like there are quite a few USB 2 options on Amazon, including this AmazonBasics 7 Port hub and 4 port options from Targus and Sabrent.
The AmazonBasics hub looks to be a rebranded version of a TrippLite USB 2.0 hub.