1930’s Linoleum (2 layers down)– so cool!

Oak Floors under old linoleum!!

I’ve been trying to find a natural product for refinishing the wood floors in the new house.
Problems:

• Polyurethane is nasty (chemical-wise has lots of lovely VOC’s) and scratches so badly.   We had the floors in our house now redone ten years ago and they have scratches from roller skates, toy cars, dog claws…
• The floors under the kitchen floor we tore out are original but worn to a different color/sheen because they weren’t waxed as regularly.  Plus they still have the backing from the 1930’s linoleum on top which needs to be sanded off.  
• Wax products you can buy have yummy stuff like xylene and cresol unless you can just use beeswax or another European wax (but they are expensive and not as durable as I’d like)

I just found a product called Rubio Monocoat and think it might be the answer I’ve been looking for! It’s made from flax, and has zero VOC’s.  Very safe and is LEED certified. 
We’ll have to sand the floors, (but really need to anyway considering the kitchen and patches from floor furnaces and electrical work,) then just paint this oil on and wipe off excess.  If we use the fast drying one it’s done in a day!  They have lots of colors to choose from but think we will just go with the natural color of the wood.
 
In the playroom we still have to lay floors (and subfloors.)  Since it’s upstairs we want something that absorbs sounds, and still not certain what we’re going to put there.  I’m leaning towards wood with an underlayment of soundproof material, or cork (also with an underlayment.)  The kids want carpet, but I’m not a fan of the chemicals in carpet or the dust that it collects.  Anyone have ideas?