Is is possible to create support order which has a graduated payments? such as 300 for 6 months then 500 per month etc?

you need to sit down with a lawyer to discuss this. The court will look at the best interest of the child, not the parent.

At the end of the day, if you and the NCP can agree on something that works, then yes. I am assuming that you are not currently in Court and simply attempting to work out a suitable resolution to a temporary problem. If the assumption is correct, then I applaud you.

Yes, you can certainly agree on payments in that wat. Have an attorney draw up the Motion and Order modifying. Can be a simple process.

If you agree to it, yes, definitely. But make sure you actually file for the modification or the AG will hold NCP to original payments ordered.