Hello,
about "1) How can we fetch or get only updated data after a specific time interval?"

I regret to inform you that You can fetch only data in specific range (between 2 sequence numbers) or after specific sequence number. We base all on sequence numbers in general at the moment.

about:"3) How do we get a created and updated timestamp of each record? to avoid conflicts because we are going to push and pull data at certain intervals, because for a few updates, it becomes a very lengthy process to get all the information and update accordingly."
We do not support dates of creation or update time stamps.

about:"4) Currently, the data being fetched is in XML format. Is it possible to fetch the data in JSON format."
We support only xml format as return.

Best Regards,
Giuseppe