Tiny Drum room .... should I?

Hi All, I have just moved to a new terraced house which has a basement garage. Inside the garage there is a small room already constructed. It measures 2.37m x 2.5m and is 2.32m high .. almost a cube, I know. There are no windows and just one single sheet metal door with some ventilation slits in it. Of the four walls, one adjoins a neighbours basement, one is against the garden but underground, another against a small kitchen the owner has installed in a separate small room and the last one (with the door) borders with the open basement/garage space. My lady wife is taking up drums :shot: and we are looking at the possibility to install a practice kit in that room so I did a rather un-scientific sound check and put my best iPhone dock speakers down there and cranked it up all the way with some beefy rock music at full blast... result: with the metal door closed I could bearly hear the music in the living room above, not at all in the garden and quite attenuated in the open garage space. My conclusions: 1. I have a lot of the sound isolation already done out of the box. 2. I need to get my studio speakers down there with a nice noisy drum track going and re-do my listening to verify my so far positive results. My questions: 1. Is that really too small a room to put in a kit to practice in? Even if I get a suitable amount of isolation in .. will it be very difficult to treat the room acoustically for a reasonable playing experience (no drum recording is foreseen at this point) 2. How do I assess the probable noise levels going into the neighbours basement? Thanks for any help in advance.