No build thread anywhere, I can send some of the pictures I still have, some were lost in digital mishaps.  De-powering the NC steering rack is much like the NA/NB units, some differences such as a special size/shape socket to remove the large rack tube nut on the side with the pinion...I made one of these tools and you're welcome to borrow it as well as there are two inner tie rod end lock washers that are to be replaced when doing this; I have two extra and you're welcome to those as well. 

My engine is 302 SBF, I was motivated after seeing your E36 project a few years ago, and for better and seemingly mostly worse I'm a Ford guy.  So I too like the suffering. No doubt about the "easy" button is an LS, not saying it's easy but certainly there are fitment advantages namely total engine height. From crank center downward, and crank center upward GM created a really short package if using the appropriate oil pan and intake manifold. 

You mentioned the weight of a dressed LS, what's the dressed weight of the Wankel ? 

In checking level on the frame rail pinch weld, placement of the level by only a few inches changes your readings.  Pics 1&4 are with the level approc 5 inches reward and this shows slightly out of level where as pic 2&3 are with the Level all the way forward on the frame rail, showing level. Also used two digital angle finders and though there was a bit of repeatability issues, both digital levels matched the regular level. 

Happy to help in anyway with your build.