I've decided to go without the "swirl pot" for now. I figure if it is an issue I can always add one later and if I do add one it will be a full 1.5ltr one not a coke can. As you've said I also dont like the idea of putting the fuel system right up next to the electrical.
Im also thinking about not using the Marlin tank and getting something else instead.
One a side note how did you attach your pipes to the tank? Can you get adapter, my pipes are 8mm?