Grumpy_Mike:
Is there any way to do it just with resistors (pull up/down)?
No.
Not and stop your 3V3 device from getting abuse.Can I have different SDA/SCL pins for the real time module
No the I2C circuit on the chip is fixed to those two pins.
However if you had a software I2C library then you could.
Is there any software I2C library available to do such a thing?