Step Up Transformer with Moving Iron Cartridge?

No. But you do need a phono amplifier with a MM 47k input.

No, but Grado made a low-output MI cartridge (.3mv) that could use a stepup device.

Low output moving iron (MI) cartridges usually do not mate well to SUTs because even though they can have very low internal resistance, they exhibit high inductance, 100 to 1000 times higher than LOMC cartridges. Manufacturers of such cartridges will usually offer guidance. But anyway I agree no step up is needed in this case.

What is your phono stage? … and the rest of your system for that matter.

In addition to what Lew said, The LOMI carts still have appreciable inductance and the step up ratio needs to be kept low (generally under 10) to avoid issues at the top end of the audio band.  

dave