So it turns out if you disable the TDGS plugin (place it outside the 757's plugins folder) the sim renders perfectly and becomes usable. Also, doing this makes the xplane menu work again. I believe doing this only disables the radar (Which I'm ok with for now). One problem remains though, and that is the smart phone main menu is still unclickable as it's too small. In order to fix that, you also have to move the 757767avionics plugin out of the plugins folder. This solves all problems but obviously introduces a bigger one which is that avionics will not work.
It's all about how the 757 uses no standard rendering for some of its features. I don't think these are unsolvable problems. For now I'll fly with no radar as I don't need it for what I'm doing with the sim. The airplane's config I'll only do once with HDR turned off, and then save those settings as default. The airplane loading and fuel, I'll do via the normal x-plane menu. It would be so great if I could use my ipad for configuring the 757, just like I can use the CDU in it through a browser.