What are the warnings that come with each of this 3 points?
Have you asked the local controlling body about the ability to build, get rid of waste?
How would you get drinking water? Rainfall catchment etc.
What percentage of the land is affected by those above points?
From elsewhere.
Hydric soils are often organic (peat or muck) and not suitable construction material. If the area qualifies as a wetland, then it is subject to federal regulation, and any disturbance would require a permit from appropriate agencies, such as the Army Corps of Engineers.
Hydric soils information