[Encounter 6.2] how to derive clock frequency

For research purpose, as a new user of SOC Encounter 6.2, my aim is to obtain clock frequency and area. I tried to place and route (with mostly "default" setting) my design. Currently I did not put filler cells and power strips. What I did was simply: Specify floorplan -> Add power ring -> Place standard cell and block -> Specify clock -> Nanoroute. My questions are: 1) There are some metal density violations. I am currently ignoring them. Considering there are no DRC, geometry, connectivity violations, following timing report is obtained. Setup mode all WNS (ns): 8.500 TNS (ns): 0.000 Hold mode all WNS (ns): 0.050 TNS (ns): 0.000 Does it mean by "clock length = (8.5-0.05) ns"? If not, in order to obtain (accurate) clock frequency, what should I check? 2) Typically, does area mean by the area of the core or I/O boundary?