The manifold should not be supporting the turbo. In my case, the turbo hangs off my rear sub-frame. Slip-joints and v-band is used to absorb any play. Engineis mounted solid, also. There is no load on manifold flange or the head.
I had problems with intercooler airflow, before I installed the fans. There definitely was not enough. Installed fans and air-dammed the area around them and the intake air filter. My scoops are wider, because the body is wider, also. No problems, since, even on the dyno with limited airflow. I do not think that the problem is with the scoops, but with the (too) high-pressure area in the engine compartment. There is not enough to pull the air through a large intercooler.
in your pictures of the manifold, I can see its a very straight design directly into the turbo, Im not sure how much stronger inconel is but that is a very long moment arm. I would be surprised if it doesnt start cracking heavily at the manifold flange. What have you done to support the turbos weight?
Also, do you have any trouble with intercooler air flow? How do you get enough flow through it apart from the addition of the fan? Is the body work enough to suck air through it?