From my experience setting up several Schroeders and observing Frank set up more:
2 screws holding cartridge to mounting plate:
Very snug but, to quote Frank, "There's just one twist between really tight and REALLY loose!"
1 screw holding mounting plate to arm:
Adjust snugness by listening. Probably not as big a difference as on a DPS or Reference, since your armwand's not wood, but still worth experimenting. There's no "right" answer. Every cartridge reacts differently depending on how it leaks stray resonances into the headshell. Listen, adjust, listen...
Counterweight screw:
See first answer, but use caution not to mar the arm stub.
Or ask Frank, as Raul suggested. He knows best.
