I'm not a Mac guy but an SSH/SFTP Client is native on Macs now and you can install SSH Sever as well. I think Linux Lite 3.8 comes with native SSH client. It depends which way you intend to do the bulk of your file transfers. Google up SSH/Macs for info. The LL side is easy to configure, almost OOTB, and you could use Remmina with it too.
Also the regarding the errors you are describing with NitroShare, one sounds like authentication issue (probably on the Mac side) and the other like a firewall setting issue (probably on the LL side)
TC