It depends.
'Mike and Mary's Pizza' is most likely a place, and a noun is a person, place, or thing. If it is a person's name, a place (such as a street name, name of a place, a city, a country, a town..) it must be capitalized. Just regular English rules.
Now, if the Mike and Mary HAD a pizza, you would not need to capitalize pizza considering it is the object. Here's an example of a sentence where you wouldn't need to capitalize pizza - "Mike and Mary's pizza was cheese." Now here's an example of where you would want to capitalize pizza - "I am headed to Mike and Mary's Pizza to get some food."
It would be rainsford falling off the yacht because at that point you wouldn't know what is going to happen and that eventually turns into a series of events.
In my opinion, yes and no
