My house has nice, tongue & groove oak flooring throughout. I'm guessing
the finish is acrylic. I don't believe it's varnish

A number of spots/areas are going bare. Question is whether or not we
should sand prior to putting down more acrylic?

A few areas have scalloping, or curl. Does sanding smooth those down?
Other than cosmetic, is there any reason to deal with those areas?

The only reason I can think of to recoat over existing finish would be
to preserve the wood until you have time to sand it.

Sanding will remove the warping in the boards. That is the most time
consuming part of the job. Getting the old finish off is easy -
getting the wood flat is not.

Do the job right. The end result is more than worth it.


-rev

Read the label of your product, it will say sand inbetween coats. A
circular sand floor machine with the right pads is best