(a) Actually, my wonderful GP confirms that whatever phrasing he uses, the local lab won't test FT4 unless TSH is abnormal. He's going to try 'FT4 IRRESPECTIVE of TSH result' and see what happens. Of course, this is England, and you may have a different experience. The T4 tests are badly standardized, apparently you can get high FT4 by one method and low FT4 by another from the same blood sample. I don't think they've ever been used for anything serious since TSH is a better test anyway, so the lab may not be acting insanely here.