Since you have already stayed for 5years, there will be absolutely no problems buying a condo and renting out the entire hdb flat.
Allow me to make applications on behalf of yourself and the potential tenants to HDB.
I would be more concerned in the financial planning part if u decided to buy the condo using CPF when u are servicing your HDB with HDB loan currently. CPF would requires yourself to set aside $117k as Minimum Sum if u are 55years, or $58,500 if are below 55years old.
Please do let me know your thoughts and also allow myself an opportunity to present to yourself this software which can identify all units for sale in a particular project during a particular timeframe.
Brandon - ERA Marketing Director