set_max_delay and report_timing (and fmax)

What's the setup relationship when you run report_timing? It should be your set_max_delay value. Note that clock skew is still used in the analysis, so it's possible to fail because of that.

I recommend against report fmax. Fmax is only valid within a clock domain, so it's report is only a subset of all paths in a design. The slack reports are the real reports that cover everything. It's possible to have a design that passes fmax but fails timing(it would have a setup/hold, etc. slack failure)