For the skewed bridge, I would consider handling it like an intersection. Create a feature line or alignment for the skewed ends of the bridge and use it as a target for the corridor at each end. You will have to end the corridor before the skew and create an assembly that consists of a single point to run along the target feature line just as you would for a curb return.
For the wing walls, create a feature line for the top of wall and one for the bottom of wall. You should be able to control the grading around the face that way.
Neil Wilson (a.k.a. neilw)
AEC Collection/C3D 2024, LDT 2004, Power Civil v8i SS1
WIN 10 64 PRO
http://www.sec-landmgt.com