Hi,Welcome to Just Answer, My name is XXXXX XXXXX forward to helping you today. lets get started.
When you say the drain hole for the washer is quite small do you mean circumference or do you mean the drain is short and you cannot get the hose down far enough in it? Half inch is really not enough to keep this from coming out I understand, you can add a piece to the drain to make it a little bigger they sell them at Lowe's, I'm not sure what size yours is but they have pieces you can get to make this a little bigger and you can make it higher so you're hose will go further in and then take a tie wrap and put around the pipe and the hose to hold them together so it can't popout, as far as the washer moving it sounds like you have to level it, can you get me the model number? I would like to take a look at that, thanks, Bryan