Here's a quick update. I've decided that I need to start thinking about how the upper playfield is actually going to mount. Solidworks lets you assemble by surfaces, I need real hardware in the real thing. I'm going to route out a pocket on the back wall (which is supported by giant braces behind), then the upper playfield will rest in that pocket. Then in the back I'll have a couple 4" standoffs helping support the cantilever.
I'm adding a loop around which will hide under the backbox (like iron man or EATPM). The loop will only be entered from the left (right will have a one way ball gate). If you don't aim well, the ball will end up draining down the left waterslide ramp.
There will be an auger elevator which you enter from the back, and it ejects towards the front when it reaches the top. I will eventually add a crank and a hand (or mini mannequin) to tie into the song (ever carry the weight of another). I was going to source an auger, or possibly build one (sections of arched sheet metal), but I remembered making a silent windchime in woodshop in high school which is very similar shape. You basically stack a bunch of sticks, but stagger them so it creates a spiral. They are held in place by running a threaded rod down the middle and squeezing the pieces with nuts on either end.