Earlier there were local hired Nursing staffs as per International standard they were transferred from local to overseas contract.
1.) Is it possible for staff to request contract change from local to overseas? (Has there been any precedent on this before?)
Not possible until he/she resign ( if the staff worked for almost 8-10 years locally) and want to come back in overseas contract only the department head can release the same opening and put it on hold for the existing staff if the age is less than 45 years old.
2.) What are the exact differences between local and overseas contract with regards to allowances?
Local Hiring are paid with inclusive package which doesn't include other allowances and Overtime days are excluded only paid in comp off.
Over Seas hiring are paid with Overtime and other allowances depend on the Grade example: paid market allowance, W&E allowance, transportation, phone allowance, furniture allowance; if planning to stay for 3 years in HMC housing. ( kids education depend on the overseas grade)
3.) As non-physician, am i eligible for marketing allowance (for grades above 113)?
NO you are eligible perhaps its totally depends on your department whether they want to transfer you to overseas when you are in 113. kids edu fees are provided, anyway your salary will reverse with increment.
(i did not receive it before in my role prior to promotion)
4.) Do HR allow renegotiation of contract following internal promotion?
Nope the department should give the approval for any promotion or negotiation not the HR.