I have this working via SSH tunnel and do not have to enable/disable proxy in about:config ever.....this can be configured on a per connection profile via System, Settings, Internet Connections. This removes the need of having to change the 0 to a 1 in network.proxy.type each time you want proxy. My steps......

In microb:

In adddress bar go to about:config

change:

network.proxy.http_port to your chosen port
network.proxy.socks to localhost
network.proxy.socks_port to your chosen port above
network.proxy.ssl_port again your chosen port

Then under System, Settings, Internet Connections, Connections

find the connection you wish to use the proxy with.......then edit....next....next....advanced.....

Check Use Proxy
then ONLY fill in the fields for Port numbers for HTTP and HTTPS proxy with ....you guessed it your chosen port number.

You may want to scroll down and fill in the Do not user proxy for section with what makes sense to you.

Last......you need your ssh command. I highly suggest creating a public key for passwordless login to the host and embedding this command in a script. I call my script pxy and placed it in /usr/bin for a quick execution to establish my tunnel, my command is as follows:

ssh your remote host -p your remote port -l your remote username -nN -D your chosen local proxy port -o ConnectTimeout=5 NumberofPasswordPrompts=1 &

Hope this helps someone, I'll help where I can. I won't be watching this thread closely please feel free to PM for help. This works flawless for me. I suggest installing an alternative browser as well as they will not bide by the proxy settings in the event you need to authenticate with a captive portal unless you build the exception in the "Do not use proxy for" section of the Internet connection