Hello, yes absolutely, you can refreeze the ice cream that you have not used, it remains perfect, its taste is not altered. If you put it back in the freezer for a while and you find it too hard, the little trick is to put the plastic pot back on the machine and do the same thing again after freezing, and you will find perfectly smooth ice cream...
Unfortunately, the accessories are not available from our suppliers. I also generally can't find any other offers when I search the net. However, it seems to be possible via the manufacturer itself. I would recommend that you enquire there directly.