Q1 No! Everyone is SIN based. Some try to commute but given the roster disruption it can be stressful and expensive.
Q2. I have been here 3 years. Number of upgrades in that time. Zero, nil nada, Zip!
Q3. The bond is SIN$142,000 over 5 years. You have to put SIN$56,000 of that up as a bank guarantee (for which the banks will charge up to SIN$5,000 on day 1) and the 5 years doesn't start until completion of conversion.
Q4 (the question you haven't asked) Its ok for an expat Captain if it suits your personal circumstances but I would strongly suggest that, as an F/O, you look in the direction of the sandpit if you want a quick command on expat terms and a career as opposed to an adventure.
Its Captains we are short of now, not F/Os, and until the package goes up substantially that will remain the case.