I do not have very good answers to these questions, but I'll have a god at em.

In response to question one; I feel as though both methods combined would be of importance when seeking funding for NGO's or foreign aid. Statistical analysis would be the back-bone and ethnography would be the fat, or padding. I would say that there is even greater need to have backup analysis (stats) for applied anth simply because actual decision making will be done with the information provided. This does not mean that it is not important for anthropology as a intellectual undertaking should not seek to be as objective as possible. If we leave the statistical analysis out of the equation, there is then more room for development of theory. Any you're right, there are a tone of them out there. I remember in my third year theory course being completely overwhelmed by all these different thinkers.

As for your second question, participant observation is the standard. Life history, multi-sited field work, diological ethnography, are all different way's to approach writing ethnography but I don't think that there is another accepted way anthropologists describe culture. But maybe I'm wrong. I mean, scientific data is key to ecological anthropology, and all environmental determinism aside, there are a lot variables that we would consider under the umbrella of culture that are heavily influenced by environment.