http://apps.leg.wa.gov/RCW/default.aspx?cite=9.41.280 and then tell me what you think.
2) See 1) above.
3) Read 18 US Code 930 here: http://www.law.cornell.edu/uscode/ht...0----000-.html paying particular attention to subsection (g)(1). Unless the Feds own or lease the whole builidng I think the restriction would only apply to the FBI offices. Last time I checked the FBI office in Spokane was located in the Bank of America building. There aren't any of the required signs posted on the main or second floor areas that are generally open to the public.