The Newton Needham Chamber of Commerce has endorsed Mayor Setti Warren’s proposal for $11.4 million in property tax increases to pay for schools, roads, additional teachers, new Fire Department buildings, and a small number of police officers. Members of the business organization were reluctant to support heftier taxes, but feared that the city’s deteriorating infrastructure could hurt its economic development, according to an announcement by the chamber. Without the additional revenue from the mayor’s three proposed overrides of Proposition 2½, Newton’s bond rating, which affects the city’s borrowing costs, could also slide, chamber members worried. Joseph De Vito, chairman of the Newton Needham chamber, said endorsing the override package was not an easy decision. The organization’s support came with a reminder for Warren that its members want Newton to more quickly address zoning and parking regulations that they believe are stifling to new businesses. Newton voters will vote on the override package on March 12.