What you are saying sounds suspiciously like the argument of a local realist. Hopefully I am misunderstanding you, because such is prohibited by Bell's Theorem. You are familiar with this, correct?Alice's measurement is indefinite to you. It's not indefinite to Alice or Bob. The nature of measurement on Alice does not change Bob. They are propagating with opposite angular momentums. Yes, because no one realized you have to understand entanglement from the point of view of Alice and Bob, not an external observer performing the measurement.
I can predict Bob's spin at any angle across the spectrum by measuring Alice. If Alice and Bob are independent, as you imply, and there is no superluminal interaction, as you also imply, then Bob's spin at any angle across the spectrum must actually be predetermined. (Which is contradicted by Bell tests.)