Also while I'm at it we have a very young fig tree in our garden (that is fruiting). However I am aware that they can grow to be approximately fuckingHUGE is there any way to prevent this or should I just get rid?
+1 for restricting the root growth, however you don't have to totally restrict it. If you sink a "box" of vertical paving slabs into the garden and cover the bottom of the hole in a thick layer of rubble you can re-plant it in that. Alternatively an old washing machine drum apparently works well.
Also while I'm at it we have a very young fig tree in our garden (that is fruiting). However I am aware that they can grow to be approximately fuckingHUGE is there any way to prevent this or should I just get rid?