Unfortunately, you're going to have to get Carpenter to 50 first, at least. I am unaware of a i70 turn in rotation that has even a passing chance of success without Byregot's Blessing.

You also need to get Ingenuity II (Blacksmith lvl 50), and maybe Steady Hand II (Culinarian lvl 37). You'll need those for 2 Star Auto HQ/3 star crafting anyway.

As for your offhand... I believe the requirements for most 3 star rotations is 397/375. So your offhand should have at least 4 control and 6 craft. All of my actually melded off hands have 4 control and 10 craft, just for a bit of over kill.