Just a random thought and I'm no expert, but I wonder if the crank angle sensor ring is bent, with the engine swap history and all? I remember someone reporting doing a clutch job and flywheel (on a manual transmission boxster) and bending one of the metal fingers that the crank angle sensor gets a reading on, by accidentally dropping or not being gentle enough with the flywheel when it was removed. They reported that the engine did not run right (or even start at all, I can't remember quite perfectly), but they reported the behavior immediately and perfectly became fixed as soon as they pulled the transmission, identified the bent finger(s), and re-bent them to where they were supposed to be, and reinstalled.
Sure is hard to say it might be what's wrong here without the history, but seems hard to rule it out completely, and the engine swap knowledge presents an opportunity for it to have potentially been messed up. (I think on a tiptronic transmission, the crank angle sensor ring would be mounted on the flex plate - on a manual transmission boxster, its welded to the back of the dual-mass flywheel.
I'll see if I can find the thread and post here if successful. In any case, cheer and good luck! Ps - just looked closely at your thread, and noticed the car is really coming along so it will be a shame if you can't fix this "no start" condition!
Edit: I found the thread with the bent crank position sensor teeth - check it out! This jibes with the "bad crank angle sensor" fault code you said you got, AND the same no start/no idle behavior you report.
http://986forum.com/forums/performance-technical-chat/56274-flywheel-differences-post440971.html#post440971
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