Thanks for your answers.
My apologies re units of measurement: the dreaded imperial/metric challenge. In Oz, most builders, timber yards (that's "lumber" to you) deal in millimetres or metres. We also put our larger measurement first. So a board might be 4800 x 150 x 50 mm or in your old fashioned terminology 16' x 2" x 6". There was a lot of grumbling in Australia when we changed from imperial to metric, but once you've worked in metric, using millimetres as your base unit, the advantages become obvious.
We have Douglas fir over here. We call it Oregon. Like all timber, top grade clear stuff is becoming harder to find and more expensive.
Looks like both self cut and factory made tape have their places. Am unfamiliar with carbide scrapers - presumably these are readily available from hardware stores as are the cutters Charlie mentioned.
When birdsmouthing long lengths I would presume that a tilting arbour table saw would be useful. For those of us without such luxuries, what other methods are available?