I think the last point there is very important and perhaps should be the focus of the entire thread. There is no policy (that I know of) that clearly regulates pages within Category:Parodic comedy sketches from non-DWU series. What stays and what goes in this extremely broad category of obviously invalid stories?
One way that I looked at it when I was into making invalid pages was that if an actor reprised their role as their character in a licensed appearance then it can have a page which, with hindsight is a bad way to do things.
Another way that I thought was surely better was if the parody had been included in some way on an official DW BBC DVD. The Real McCoy was deleted for being unlicensed despite being included in its entirety on the Earthshock DVD and Pakistani Dalek was deleted for being unassociated with Who despite clips being featured in More than 30 Years in the TARDIS.
I don't know what the solution is here, but I thought I'd bring it up.