My apologies for the delay just getting back into the groove of things.

Wood floors are installed with tongue and groove strips.  

Glad you're getting back in the groove of things, I'm sure lots of lessons were learned in the process and you're more experienced than before.

(granite, tongue-and-groove ceilings, 3-piece base molds, etc.)

There are a few problems when using this option on your flooring:Unless your floor is absolutely perfect and level, you will be able to see every bump, groove, and lump through the thin vinyl plank.The backing, which is supposed to stick to the floor, doesn’t always stick.

The master has panel board and I am attempting to save time and money by not removing it and just skim coating the grooves and then adding texture later. 

The interior wall surfaces are all tongue and groove boards (cedar), there are visible nicotine stains on the air returns.Every single surface will need to be cleaned in some capacity, but I am left scratching my head at effective solutions.I've found a few anecdotal recommendations about using white vinegar or TrisodiumPhosphate, but when you need to scrub the walls and the ceilings of a 1700+ sqft house that seems pretty daunting and time consuming given that it is tongue and groove.

If the market is filled with empty rentals then you have to hustle to find renters or end buyers (if you flip)I have done 100's of deals and its very rare the deals just fall in my lap, and the market seems to change right when I am getting into my groove. 

For the paint, I would brush the grooves first, then roll.

There are so many choices today and with the way flooring gets worn and trends change, it's great to have a product that goes in and out as easily as it does, once you understand what quarter-round shoe is and how to install that with ease.And while it is trending out due to all the options out there, and has all sorts of problems of it's own, I still really love a 3/4 inch tongue and groove solid plank hardwood floor.