Beeing able to configure syslog retention time also per node (deviating from the global syslog retention time configured in server configuration) would be great.
If you've got some Hosts, which are monstrously chatty with syslog, you could restrict syslog-retention time for those to a few days without throwing away the syslog-data from other devices...
There's a feature request for this one: https://track.radensolutions.com/issue/NX-1557
For your other feature requests, I suggest creating an account on the page above and registering them there, too. :)
Unfortunately, I'm not able to register at YouTrack, it says "License limit exceeded. The request cannot be completed." - Otherwise I would've been more than happy to just create that Feature-Request... :)