Let us know Ben how you get on with it, hopefully the flue will work. Normally peeps have a vent in roof where the flue goes straight up. I know what you mean with hoses thou, I've got mine just at the right length and put them in the plastic clips so when you close the door they don't get caught in the door, also put a load of sponges behind so it don't move to much when closing and opening back door. If you see my connectors below shower I just disconnect there to drain out shower so not gotta sod around with the drain screw.
Just bought the thermo red 8mm ID much fatter than the 6mm ID orange thermo hose tried it yesterday and really good. Like I said before I don't have my water really hot just Luke warm of which the thermo holds the heat more than the normal yellow hose