I concur with the previous posters. Even though the trailer with be static, you must leave the black tank valve closed and allow it to fill and then dump it as necessary. Leaving the black tank open all the time will cause disastrous results. The tank will develop the 'black hills syndrome' which can require replacing the tank..
As far as the converter goes, the trailer will require some major modifications if you want to remove it. All of the trailer lighting and the furnace fan are 12 volt
, and will not operate on 110. Also, if the refrigerator has electronic controls, these are also 12 volt