Hi, I'd like to help you with your question.
Whenever you go to do something significant in your life and you have reservations about it, then you are trying to tell yourself something. Remarrying your ex sounds great on the surface, but if you feel hesitant about it, then you have reasons to not go ahead with it.
One concern that stands out to you and me is why your ex is unwilling to take time and date for a while. What is the rush? If you have been divorced long enough that you married again, had a child then divorced, then you have been apart for a while. Dating for a short period would not hurt anything. It may also help you determine if this is a good move, which is something your ex is seemingly not concerned about. That is something to consider.
Also, did the issues that broke you up in the first place ever get resolved? If you still have have not resolved them, then they could resurface after you marry. You may end up in the same position you were in before.
Your requests to date first and to go to counseling are very reasonable. You do not want to make the same mistakes again so you want to take steps to ensure you are making a good decision. That is very wise. If your ex is insistent on hurrying into the re marriage, you may want to back off and see what he does. If he is still insisting, then you may want to consider this a bad decision.
I hope this has helped you,