Port 1035 i a kind of an artifact - my former router had a biult-in ftp server and didn't support any kind of forwarding, so I had to set up NAS as a DMZ, and change its listening port. Nevermind, switched back to 21 as suggested.
I've also set up whole ftp server again, deleted and recreated users and their shares, nothing changed.
Regarding port 2962 - I think that command line ftp client works in active mode, however fire ftp set up to work in passive mode reports connection through 207,127, which translates to 53119 and it is not in a passive mode range...
Tried to connect with:
command line - connects, but cannot bring up content, reports root as a restricted folder
fireftp active mode - same as above
fireftp passive mode - same as above, additionally tries to connect through some strange ports
windows file explorer - connection timed out, make sure you have permission to access that folder. Tried to connect with only username - asks for a password, proceeds to getting contents of a folder and reports time out again.
IE - trying to connect for last 30 minutes, progress bar at half
firefox - after about 15 minutes of logging in looks like it did, but displays an empty folder (which isn't)
All of it points to problem with users permissions. So I gave all the accounts full access to root. Didn't help.
Tried to connect locally again - command line ok(reports root as a restricted directory), fireftp active - the same, fireftp passive - cannot connect, same as firefox, IE and file explorer.
It looks like I have two problems here - one would be with NAS's passive mode, which seems not to work, and second one with my router, which seems to direct traffic improperly.