Yes it is your call at the end of the day and you need to pick families that are on the same page as you are. You could be honest and just say thank you for expressing interest in my home daycare. I have chosen families that I think will best fit into my daycare group. I am sorry to say that all of my spaces are now filled. Good luck with your childcare search. Most of my families contact me by email so it is a lot easier to send an email back when I am filled.

If there was something specific you could do the parents and future caregivers a service by bringing it to the parents attention since you aren't taking them anyways doesn't matter if you offend really. But to tell them that their demands are outside the bounds of normal daycare or whatever might help them to temper their requests and actually find a caregiver.

I don't have specific rules for parents but within your contract you will have expectations set out that any one of them if broken is a breach of the contract and grounds for dismissal. It will be up to you to determine how serious the infraction is. I have had parents make excuses and pay late - as long as they pay I am ok with a day late once I get to know them, parents forget to bring stuff you ask for it happens, will be up to you to determine what your limits are. Parent having a tirade tantrum at the door leaves and doesn't return no questions asked.