Answer 1: Uplink ports connect the distributed switch to physical NICs on associated hosts. The number of uplink ports is the maximum number of allowed physical connections to the distributed switch per host.
Answer 2: My recommendation would be to create 1 vDS and create Port Group.
Answer 3: Recommendation is to be on vDS, if you are having standard switch the, it's your wish. I would recommend for more information and in-depth understanding on vDS, please see https://docs.vmware.com/en/VMware-vSphere/6.5/com.vmware.vsphere.networking.doc/GUID-D21B3241-0AC9-437C-80B1-0C8043CC1D7D.html https://www.vmware.com/content/dam/digitalmarketing/vmware/en/pdf/techpaper/vsphere-vnetwork-ds-migration-configuration-wp.pdf
I did end up creating a single vDS with distinct distributed port groups as noted. Thank you for replying.