The 13,000 Btu/lb figure is reasonable, if you assume that there's almost no moisture. That's not too far fetched for sawdust and wood chips. The average is around 8,000 Btu/lb, but that's for logs, which typically contain 20-40% moisture.
As far as "no visible emissions," that doesn't mean no particle emissions. That "nice" wood smell is due to aromatic hydrocarbons, some of which are listed as carcinogens. These PAHs (polycyclic aromatic hydrocarbons for you chemists out there) often exit the stack as gases but quickly condense to form particles.
I'd say wood is better than coal, but it's not a magic solution. It may be a solution that people can live with, though, and that would be magic enough.
Andy