Is there a way to make a bridge that I'm not seeing, or is it just that complicated?
None.
No, there are currently no bridges.
The best you can do is fake it with terrain and the Mar Sara Bridge doodad.
None.
Ok, I was sitting here making a map, and for like 30 minutes was searching for a bridge. I had just assumed that such a basic element of a map would be in the beta GalaxyEdit, and so when I didn't see one, I was thinking "Surely Blizzard isn't going to make us manually design a bridge, wasting minutes to hours of our time when they could just give us a flexible bridge doodad..."
I guess we'll have to wait and see if they patch it in or if we'll just have to wait until July 27th =/
None.