Have done #1 and #3 by bike, but not sure on #2.
Crossing Over, Step by Step
Weekend in New York
By SETH KUGEL
At least a dozen bridges from Manhattan to the other boroughs offer pedestrian lanes — and a bit of adventure. So why do most visitors merely cross the Brooklyn Bridge, then call it a day? Here are three bridges worth the walk, especially for the (most un-Manhattan-like) neighborhoods that beckon on the other side.
1) WILLIAMSBURG BRIDGE
This 7,308-foot suspension bridge was the longest in the world when it was completed in 1903. ...
2) MACOMBS DAM BRIDGE
The most human-scale of the three bridges here, with only four lanes and no trains, this is a metal truss swing bridge completed in 1895...
3) QUEENSBORO BRIDGE...