"Took a look at my contol arm bushings and, well, they almost don't exist anymore."
These are not likely to affect a rough ride much. They CAN be an indication of the rubber deterioration you can expect at more critical points. They can also affect noise, handling, steering shimmy, etc.
For RIDE related issues, look first to those areas where weight is supported. Upper spring mounts, subframe mounts, and any shock attachment rubber not replaced with the shocks.