Problem 1 is a geological/engineering issue that can be guarded against but almost never guaranteed unless pretty high end construction is used – not likely for production homes. Best guarantee is test of time – I use 5 years as my criterion. More for unusually steep slopes/hillsides (but I am never interested in those anyway at any price) and less for flat lands.
Problem 2 may be resolved if you know someone very familiar with builders. Some real estate professionals on the board may have some knowledge of various builder’s labor practices.
But because of problem 1, why bother with problem 2?