If it did take forced field renames... that could seriously fuck up the csv output of the results... I would think.
Yes, definitely do not rename the inputs. That would "work" in that you could submit, but I have no idea what the requester would see and there's no way to prevent other users from doing the same thing but using different names, which would be a mess on top of a disaster.
Would be interesting to test to see if you get a new column for every name submitted or if the setup in mturk determines what columns you get when you publish.
And you can't check two radios with the same name in the same form, as far as I know, even with javascript.