Check the Fogger thread again for the o-ring issue/fix. I was having a major shorting problem which I fixed using a wedged-in spare o-ring (from the included spares bag). As far as juice flow, well I think it's all in how you constuct your wick and coil. Because the juice has a relatively long distance to travel between the outer tank and the center of the coil deck, if you wrap your coils too tightly they will strangle softer wicks, like cotton or silica (by itself), which is why I think the stock setup has an oxidized hollow mesh roll with a silica string inside. The mesh, when fully oxidized, becomes quite stiff and prevents coil choking. But you certainly dont need the mesh. If you do use mesh, it is wise to fully oxidize it to keep from shorting.
I have rebuilt the Fogger v2 six times so far and the only problem I still have is proper wick speed. Now, I likely pull too hard and I certainly am guilty of excessive chain vaping, so I have added the extra step of one dry (non-battery-fired) pull before every regular pull and that seems to have mitigated the wick speed thing so far.
