No they're not natural hosts for clown. I have read that some people get them to host clowns, but it is very rare and usually not to good on the anemone.
I have owned two condy one green and one purple. The green one seemed very mean and stung everything and always moved. My purple one on the other hand I still own and seems to be harmless as it hasn't stung or killed anything and stays pretty much in the same spot.
In general a condy is not a very good choice because they're fish killers if they get the chance and it guess it's hit or miss on if you get a good one or bad one.
I love mine though. He has been in the tank for about a year and hasn't bothered anything, but then again I only have two fish in the tank. black clown and 1 lawn mower blenny.
I think the main thing condys are good for is to test yourself and see if you're ready for a different one. Condys are a hardier anemone and after owning mine for some time then I went to my LTA and he is doing great to.