The look which defines Hilton Head Island was part of the old zoning regulations. The town might be wise to retain some of these regulations, such as buffer zones and signage restrictions along main corridors.
Another suggestion would be a Hilton Head Historical Preservation Society which could certainly forestall at least some of the potential urban sprawl.
In terms of sustainability, any new commercial development needs to be tweaked by civil engineering standards suitable for a barrier island with an encroaching sea level and changing climate. The planting of forested wind breaks, a timeframe for fill dirt to settle before constructing tall, 60-foot buildings and a requirement for high-capacity infrastructure to protect our marshes would all be good ideas. Also, a new height for finished floor elevations on any new construction is needed.
Today's foresight could possibly forestall problems in the future. That includes a moratorium on development.