I rarely have found need for bridges but when I do I've been driven crazy by the lackluster tools and options.
1. Please, please, please let us change the height of the bridges. Sloped bridges would be ideal but even if they have to remain flat let us raise and lower so we can bridge land gaps, canyons and high shorelines.
2. Relating to height... we should be able to stack the entrance "stairs" to climb up or down or out to the bridges. My most recent problem was with a jagged shore, when the bridge got to the shore it was too far away to connect with the stairs but too close for another bridge section. This could also be solved by allowing shoreline terraforming.
3. Stone bridges???