For an Electrician - Power breakers keep flipping off?

The fact the the house is old and has not been updated is a problem. If the house is not legally set up and a rental property then I am sure there are other things to worry about such as fire protection and co detectors. Any where you live you should have a lease or some type of agreement with the owner which can protect you as well as him. In this case if you complain to the town they may condemn the building and everyone will be evicted! On a 15amp breaker there should only be about 7 devices on that circuit to safely operate. With all the overloading you will eventually ruin the breaker and one of 2 things can happen either it will fail to work or it will overheat and start a fire.Be safe