Answers to your questions inline
1) There won’t be synchronisation issues due to different crystal frequencies. 32khz crystal is used for
the internal clock of ds1307 only, means only to update the registers of rtc. While we try to read, the
data is copied to a register from where we read it, while the actual data keep on updated without any
disturbance
2) You should get I2C code running in your MCU, which will enable a pair of pins as sda and scl. The
code will be complex, but you can download it from internet
3) You can set the time and date by setting the registers of rtc. It can be done in both 12 hour or 24 hour
mode. Those details are available in the datasheet.