If you own the home you don't have a landlord. If you rent the home your landlord should have a key but can't enter without giving you notice and just cause. They can enter without notice in the event of an emergency
No. Thats just weird. There is no reason he should have access to your home. The man sounds like a perv. Id watch out for him. i guess if the property is his he can come in the property but he has no legal right to a key to your private home, esp if you own it. Dont ever leave that key anywhere he can get it to make a copy either. if you have an emergency key hide it WELL!