Can I invite a friend to my room or a short visit? Do I need to notify the visit to the hotel staff?
Yes, you can have a guest.
Absolutely. Parking could be tough.
I think you can pretty much do what you want...no one bugs you and price isn't per person or anything but there is a maximum occupancy per room so don't go over that.
Not an issue. No need to notify hotel staff unless your visitor is staying overnight.
It won't even raise an eyebrow.
Get an answer from Louisville Marriott Downtown staff and past guests.