BCLR has been replacing ties and doing a lot of brush-cutting along the whole branch. As far as going beyond Route 88, I doubt that will happen. Past experiments bringing in plate steel have not come to fruition. DBS does a fair business (mostly centerbeams and the occasional boxcar). Mid-City, like any scrap dealer, is subject to market forces, so its boom or bust. They actually lease some high-side hoppers on their own.
Getting back to west of RT88, the environmentalists would probably go nuts since most of the track has sunk into the swamp. It would take a lot of money to restore it to Mid-City's annex operation. As far as new business, I'm afraid both Westport and Dartmouth would never approve of any business that would use rail. Dartmouth is all about medical facilities.
A lot of the branch runs through large wetlands (especially between Reed Road and Hixville ) and east of Faunce Corner Road (Paskamansett Rive valley).