in yr case, if u decide to keep renting the apartment, under the contract law...
1. u must sign a new contract
2. yes, 1 year binding and 1 year non-blinding
3. yes, both of u must pay new stamp fee
my suggestion... no need to sign a new one since the market might going down later, then u can ask the landlord to reduce the rent and even keep the old contract rental price... good luck