Two Words, Two Meanings

No, and strict serializability is actually the weaker of the two, since it only constrains whole transactions while plain serializability constrains every individual object a transaction touches

No, serializability only requires equivalence to some serial order, so a transaction may be ordered as if it ran earlier and read stale data; strict serializability adds the real-time constraint

Yes, because serializability orders transactions by their commit timestamps, and a transaction that commits later can never be placed before one that already committed, so its reads see the newest data

Yes, because every single-key read is a one-operation transaction, and serializing one-operation transactions is the same requirement as linearizing them, so those reads always return the newest committed value