I'm thinking pine flooring would be very soft. In the days past, "Heart Wood" pine flooring was used. My house that was build in 1899 has it. But it's heart wood. The problem I see is to find enough old growth pine with enough heart to make flooring nowadays would be hard to do. Not only that but around here most of the pine has been replaced with SYP which grows faster and doesn't have the same heart wood hardness as other pines.
You may want too try calling architectural salvage yards around the RTP area for heartwood pine flooring, but be expected to pay for it...
Just my 2 cents...