hi sunlight,
in answer to your last question: as long as you go via the epoxide there is no reason to start with the iso instead of the safrole since the 2,3-epoxide (formed from safrole) will give the desired 2-ketone, too. (ref: houben- weyl, vol. 7,2,a, p. 932; comptes rendues 184,1335,(1927))
otto