PR4100 volume / drive configurations

I have a PR2100 with 2 x 8tb red drives as Raid 1. I’m considering purchase of PR4100 and would like to config as:
1a)- move the PR2100 drives in same config (raid 1), to the PR4100 (for 8tb avail), and
1b)- add 2 x 14tb red drives as a separate set - possibly as spanned (for 28tb avail) or otherwise separate Raid 1 set (for 14tb avail). I assume these configs should be do-able, to have drives configured as two different sets, with one set Raid 1 (2 drives), and one set spanned (2 drives)?
2a) - If the above is do-able, I gather they would look like 2 logical volumes? One Raid 1 set, and one spanned set?
2b) How would access to these appear externally? Would the share names be affected to identify physical volume, or just that any shares would be assigned/configured to either the Raid volume or the spanned volume (as part of creating/administration)?