#2 douglas fir is typically used here in the west and is required for structural unless engineered is used.

we used kiln dried #2 doug fir here in California.

We have three grades in use in my area. SPF (spruce-pine-fir) then Hem-fir, then Structural fir, which is the very best ($$$)
SPF is typical whitewood, quite high moisture content, and has knots you'd expect in framing lumber. hem-fir is a different species, reddish color (smells like pee). Structural fir has no large knots, and seems to me have lower moisture content.
I'm in northern Virginia.
Casey

Is the yellow pine the southern variety? If so, it is hard enough to be used for flooring and is commonly used for pressure treating. As framing lumber it will be stronger than most other softwoods and warping would be highly dependent on how much it is dried before sale. A contractor might not like it because the resin can gum up saws. I would think it would not be cost effective as framing lumber unless you were near a source.

Whatever the species, the grade should be no. 2 or better for framing.