I agree with mimi and crayola, it seems like a lot to take in. Perhaps if it were shortened and more to the point it will be better understood by all parents. I too would remove your comment regarding your work experience and also the comment of putting the kids ahead of the parents, rather word it as "more beneficial for the children".
maybe provide a proposed updated sched for them to view:

7 a.m.- open
(7 am - 7:45 am all drop offs must take place due to travel to school/parks etc.)
care will not be provided for any drop off after 7:45 (payment will be due)
8 am children and I will be en route to school drop offs/park etc.

rest of schedule


5 p.m.- final pick-up
(any pick-up after 5 p.m. will result in __$ late pickup fee, due on arrival)



short and sweet! you dont need to explain much reasoning, just what you expect and add: termination will result in breach of these set times. thakyou