I’m looking for a routine with limited bending motions due to a bad lower back. I don’t think hanging leg raises will bother me and I’m aware of leg lifts and planks. What other limited or non-bending exercises are good for your abs? Are there any video routines that fit this request?
Look into Janda’s they work great, very low stress and it’s the opposite of a situp…like a lie down I guess. You begin in the up position like a situp, but you lie down, less torque on the back, and they don’t hurt…until the next day 
Front planks, 4, 3 or 2 point as you get stonger.
Side planks
Glute bridges.
As always Quality, not quantity.
As I am just coming back off a back injury I do a ton of core work with very little bending.
My current favourite is to take two balls, roughly basketball sized, and get into pushup position with one hand on each ball. Then I roll the balls together and very carefully switch hands while remaining in the pushup position. You can lift one hand at a time and transfer your weight to the other ball. It is not easy.
You must keep your back straight and your hips square to the floor. This works the hell out of your transverse abs.
Another one I do is to plank up, with 4x5lb dumbbells next to my left hand. Again, keep your hips square to the floor, and lift your right arm. Pick up two of the weights and set them down next to where your right hand goes. Then lift your left arm, and pick up the other two and shift them over. Stay in the plank and shuffle them back the same way.
I do this maybe 5 times, fairly slowly.
If you have a swiss ball there are others I can tell you…I do this stuff 3x per week with a physiotherapist and trainer at the moment as we make sure my back won’t get damaged again and I feel like I know every conceivable exercise that meets your requirements as a result.