I can't believe you don't have a way, whats so ever, to monotor the sound quality while recording video! What is the point?
Not even with the AV in/out? Is there any posible way with the t5i? Also what is the diffrence between the t4i and the t5i? I almost bought the t5i tonight untill I could not plug in head phones. Can you not do it on ''playback'? Is there a audio level or a audio level meter??
My first Canon was a Canon QL, I got one for my 12th birthday.
Nothing directly electronic like a Sony Lanc but for DSLRs there are TONS of shouder rigs with things from just carrying the camera to full monitor support and power systems. Where you
can dial manually whatever focus you want.
Here is the basic cheapest shoulder rigs
This is something you were looking for perhaps
It is included in this shoulder rig and if Got my wish to take my Canon and be a wartime correspondent/ Photojournalist this is what would carry my Canon. I am pretty sure it beats everything you asked for and more. A lot of stories out there to be told.