Yep on all of that. For purists, the hit version of "Shaving Cream" from the 70's was by Benny Bell and is just hilarious.
If you are usenet savvy, alt.binaries.sounds.mp3.comedy gets more Dr. Demento files posted than you'll ever find the time to listen to. I believe they are rips from his weekly radio show, which has existed for decades, so don't even think about completing any collections or anything ridiculous like that. I worked at a radio station before that let me have their entire backlog of Dr. Demento radios shows (on 12" vinyl). I probably still have them somewhere (circa early 80's) if I didn't sell them already. There was a couple of other radio comedy shows that featured a host playing bits (Dick Cavett hosted such a show, plus someone else whom I've forgotten) that was pretty good stuff; I have a lot of that stuff, but I'd need a bonus life if I was ever to consider ripping the stuff to mpeg. I'll end up unloading it all on ebay one day and whatever fanatic buys it will surely dump it all to mpeg for "preservation".