[walterk01]

You dont need to set up a workgroup etc since its not going to be samba but the proxy account will not be able to save anything on your main account unless theres a shared directory.
I guess what could be done is switch to or create a directory on the proxy account and have rtmpsuck download to that and you wouldnt have to worry about permissions and shared folders but of course you'd have to still move whatever files you saved to your main account anyway.
As for doing it on Fedora, like ubuntu Fedora's default gui is gnome so it should be exactly the same or similar.
Did you try running rtmpsrv?
If the syntax for downloading was generated, then it definitely is the lack of a shared directory, when i first tried rtmpsuck i was stumped as to why it wouldnt save anything while rtmpsrv was generating the syntax.
Lack of a shared directory was the problem.
I decided to stick with rtmpsrv, just use that to generate the syntax to download and after exiting the proxy ,canceling the monitoring rule invoke rtmpdump, rtmpsuck is really only supposed to be used as a last resort when rtmpdump fails at least according to the old 2.1 documentation maybe its changed, i havent read up on it.

Edit:
Heres what i discovered for 2.2e on my system.
rtmpsrv now generates the syntax and automatically begins downloading the file, if its invoked in shared folder/partition so rtmpsuck should not be necessary.