This far down the thread, it could be easy to forget what Dave said in his OP, but having re-read it, I'd say my tastes in folk music are fairly close to his.
I do go to a number of events where "source singers" or their followers are the guests, and while I enjoy listening to them, I don't really feel like going out and learning a 40-verse ballad myself.
I do enjoy unusual line-ups, including a "bit of Brass" as in Brass Monkey or Bellowhead, and much further back, was blown away when I first heard the likes of Steeleye Span and Fairport Convention.
What I really don't like is people (usually younger, but not always the case), messing with much-loved songs and putting a thrashy rhythm on them, chopping up the words until they don't make sense any more, warbling all over the place until the original tune disappears (See previous posts re ER!).
Yes, and excessive speed does absolutely nothing for me: I like to be able to identify and enjoy the tune. I just LOVE slow airs: that doesn't mean that every tune should be played at slow air speed, but just let's have a little sensibility and musicality.
Parodies? Love the good ones, which stay nearest to the original words, but not keen on rude or smutty ones.
And please don't preach or tell me who to vote for if you're the esteemed guest: not needed in your between songs speech: and keep the balance between playing/singing and talking right. Some performers just talk too much!