Answer: This is a very broad question, which is why the answer will have to be general. What follows are some of the major issues that occur.
Answer: First, it must be noted that since tenants are not “owners,” and therefore, the caselaw and statutes that might apply to the latter do not necessarily apply to tenants in manufactured housing communities where the Spaces are rented.
Answer to Question No. 1. Generally, an "Act of God" is considered to be a natural disaster that is outside of human control. That would include earthquakes, windstorms, floods, tsunamis, etc. If you are asking about insurance exclusions for Acts of God, you'll have to read you policy.
Answer: Here is a quick primer on ORS 90.727, the hazard tree statute, which was enacted in the 2013 Legislative Session:
Oregon Law.