There was some impact if you choose the "evil" route. Nothing like nuking the BoS base and having the remaining pockets of BoS soldiers tagged as enemy. Too bad you could never officially join the Enclave.
Addition to "Tranquility Lane" section
There's actually yet another way to complete the Tranquility Lane section.
The old lady mentions something about a fail safe device. You have to play music by interacting with the objects in the abandoned house. The order is broken radio -> glass...
