@Ken Fisher - some of those pros are here on Houzz, in fact have already commented on this thread. I just don’t appreciate folks who don’t have actual experience stating an opinion as fact, on a forum where others come to for info. For example, stating that the large amount of bleaching red oak to look like this, when this look is the only outcome that would result from bleaching (you wouldnt get a different variation - and we didn’t do a ”large amount of bleaching”), further demonstrates the lack of actual experience. Question - if we wait until summer and do nothing, will it simply work itself out or cause long-term issues if not addressed now?

Yes but it requires 2 stains. This is due to how the stain will absorb for different breeds. If anyone tells you to use a poly with a stain, run. As it wears, it shows the wood below quite easily and thus is not good for flooring. Instead, sand down the area where the two meet, and take a stain you like applied over both in a small part of it. Let it fully dry. This will give you direction if you need to get a darker or lighter or color difference you will need to correct the difference. Keep in mind, you can mix together stains to custom make what you like!

Restaining from dark to light isn't easy, but the preparation process for floors takes off enough surface that it actually is easier than refinishing a piece of furniture (or kitchen cabinets) would be. But your contractor is right that there could be some stain that has been absorbed into the sides of some of the flooring boards that would become visible with the process. So a test is the only way to know for sure. If the test looks good, you'll still have to evaluate after the sanding process is complete. But why is the contractor suggesting wire-brushed? That is more work for him and less desirable for you. Talk to him about doing the project without the wire-brushing!

All I want to know is, is it ok to apply a floor stain on top of an existing floor stain (there is no finish at this time) and then add the 3 top clear coats which will be water base. Or will this jeopardize the quality of the floor (ie cause peeling etc) down the road? The stain product used was Duraseal 50% Weathered Oak and 50% Dark Walnut. The stain that would be applied on top of that is that same product (the 50/50) as option one and for option 2 it would be just Dark Walnut that goes on top of the 50/50. Note: the 50/50 mix was applied last Friday. So the only thing on the floor at this time is just the stain color. All stain colors mentioned above are Duraseal.