Pictures please.

I painted all but one wall of my knotty pine paneled FR white -- BM SImply White, (which reads very white, at first I thought almost too white, so decide just how white you want to go!) I am very glad that I did, although I have liked some knotty pine in past houses -- just not 4 solid walls of it!

Would it be possible to cover the floors, or perhaps look into having them re-stained a neutral dark brown?

My entire house is knotty pine of the lowest grade. I painted the bathroom in sealer, then 4 coats of white but the tannins still bled through. If I ever have the courage to cover the pine I will do it with sheets of 8 x 4 faux bead-board that I can paint easily and can be taken down again if the new owners of the house choose to after I am dead.

Since you live in a barn house, the knotty pine is very fitting for your type of house. I wouldnt do anything with it. I most certainly wouldnt be painting floors. I cant even imagine the maintenance nightmare that would create. My suggestion is to enjoy your more unusual unique type house the way it is, or sell it, to get the type of house you really seem to want. We havent seen any interior pictures, but, the exterior looks to be a very nice lookng house, even though the picture is in the evening, so we cant see all of that either.

Most foolproof, and probably cheapest, thing to do would be to restain that concrete floor.

I my own self with probably use a dullish dark neutral color like a dark cocoa.