Balance them within the reason. I think method #2 on the above mentioned site is a good alternative, it only requires 4 short cables between the batteries. This is what I am using with my 3*12V parallel. Method #3 looks more like a wire nightmare to me.
As to your initial question - yes, I think loads should be applied in the same locations as chargers. There are battery post extenders, or make a bus like in the pics above. Part of the problem is that your chargers and loads are not optimal already - there should be one inverter, one solar charger, and one load wire from the rig. I don't understand where converter comes into play here - it is normally hard-wired somewhere upstream in that "general" DC wire of the rig.
