The Toll Brothers, who want to build luxury apartments in the Gowanus area, got a boost last week when the Land Use committee of Community Board 6 approved the necessary rezoning plan. But they still face some pitfalls. First, Councilmember Bill de Blasio is threatening to stall further approval of the project in order to get building heights capped in Carroll Gardens. Second, the Toll Brothers are losing money: their housing revenue fell an impressive 41 percent in the 4th-Quarter report versus last year, which dropped their stock five percent before this morning’s bell. We wonder what their investors think now about building condos next to a polluted Brooklyn canal on the cusp of a recession.