I agree with you about 'for free.' The OED says it is an American usage (as is 'for real'); first examples are from the 1940s. There is a suggestion from an American dictionary that it is the result of a confusion between 'free' and 'for nothing' (although I don't see how that would explain 'for real'.)
On the previous topic, it appears that 'for' is sometimes added to 'hate' as well as 'love' - perhaps for the same reasons as I suggested. In todays' 'Observer' a New Zealand schoolteacher at the royal wedding is quoted as saying, 'We'd hate for the union jack to disappear from our flag...'