We have found that a macOS client just ping-pongs back and forth between the two ports with no increase in performance. There is an increase in performance with only a macOS server that is connected to multiple clients. To get link aggregation to work, the switch must be capable of supporting it and the two switch ports connected to the Twin 10G must be configured as bonded ports.
No, you cannot. The Twin 10G supports connecting to only one computer. You may connect only another Thunderbolt peripheral to the second Thunderbolt port of the Twin10G.
