Putting aside everything you should mentioned, common sense says that going to an MA program will increase your chances into getting to a PhD program.
First, it will show the committee that you are capable of doing graduate level work in philosophy.
Second, it will show them that you are committed.
Third, and the most important point, it does not matter if go to an MA program or not. However, what is important is important to the committee is to see a person who is developed philosophically which is more likely to happen if you are an MA student.
I am sure that after attending an MA program, you will have by then a better writing sample and statement of purpose which are important if you want to increase your chances.