Q2 - the St. Regis branded properties do not participate in the Platinum welcome amenity of choice program. The mug was most likely your Platinum welcome amenity despite the erroneous letter that accompanied it.
Q4 - old signage; I'll let the folks in the Asia/Pacific office know about it.
I haven't got a clue as far as the other two questions are concerned.
Best regards,
William R. Sanders
Specialist, E-Communications Department
Starwood Hotels & Resorts Worldwide
[email protected]