You don't have to do anything to prepare for a SC. You don't have to replace VANOS seals for FI; only if you need them. Google DrVANOS for a kit.
Conducting a compression test is not required, but it will give you a general idea of the health of your engine as well as an initial base line. Conducting a Dyno would be a good idea as well for the same purpose. However, Why in the world would you want to turn the engine over by hand for a compression test? While noting uniformity between cylinders is the point, your probably not going to get a reading that is anywhere near what others get.
There are some suggested actions you take, though not required:
-Replace fuel filter if it has more than 40k miles on it. You will find that FI cars are much more sensitive to changes in fuel pressure.
-Replace fuel pump if it has more than 80k miles on it (for same reason above).
-Replace MAF if it has more than 100k on it. FI tunes are sensitive to changes in metered air.
-Replace or clean your ICV.
-Replace your cooling system when installing SC if it has more than 60k miles on it. Why? Because it's easier to do with all the crap out of the engine bay.
-Replace any old vacuum lines if re-used; SCs don't like vacuum leaks.
Some people will suggest the items below, though it is unnecessary. They are certainly helpful though.
-Oil pressure and temp gagues
Oh, you might have more luck getting FI info on the FI page.
2004 330i ZHP ESS TS2