Is it legal to sign a contract to pay mortgage and property management fees?

Legal. 1. You must pay a down payment, then sign a house purchase contract and find a bank loan.

2. Pay the monthly payment on schedule (note that you owe the bank at this time, not the developer; If you don't pay the monthly payment on time, the bank has the right to auction your house according to the loan agreement between you and the bank, and then your down payment will be paid in vain.

I haven't heard that you have to pay the property fee before you take the house. At least I didn't hand it in and no one urged me.