Re: arcfour
Could you release this change as next major release, please.
I think it's big and wanted enough for it.
It will be released within few weeks.
So far I know OpenSSH server support non-encrypted data-transfers (i.e. only encyption for login data) if compiled with the apropriate flag. Then the cipher=none can be selected. This is disabled (at compile time) for security reasons at most (all?) binary releases but could be enabled by compiling the OpenSSH server manually. WinSCP should support this too for the sake of completeness.
It again depends on support in PuTTY.