In consideration of the landowner's curative amendment, the Board of Supervisors shall consider the plans and explanatory materials submitted by the landowner as well as the following factors: the impact of the proposed amendment upon roads, sewer facilities, water supply, schools and other public service facilities; if the proposal is for residential use, the impact of the proposal upon regional housing needs and the effectiveness of the proposal in providing housing units of a type actually available to and affordable by classes of persons otherwise unlawfully excluded by the challenged provisions of the ordinance or map; the suitability of the site for the intensity of use proposed by the site's soils, slopes, woodlands, wetlands, floodplains, aquifers, natural resources and other natural features, the degree to which these are protected or destroyed, the tolerance of the resources to development and any adverse environmental impacts; and the impact of the proposal on the preservation of agriculture and other land uses which are essential to public health and welfare.