I need some advice on multiple things here:

I noticed this morning our hives are doing this (see pic).
The weather is very humid, about 70 degrees. We still have goldenrod out so have not harvested honey yet. I am not sure why they are bearding like this.

Now to the hives:
The right 2 hives are from NUCs, the left 2 from new packages.
The leftmost hive is putting honey in its first super, but very slow.
The 2nd from the left does not even have the 2 deeps full -- the bees are refusing to build out comb on the center frames in the top deep. (They are new frames, wax coated from a well-known supplier) Not sure why they refuse to build them out.
The 3rd from the left seems to be going good, starting to store honey in the 3rd super.
The right most hive seems almost abandoned -- no idea why/what happened. When I checked it 3 weeks ago it had one honey super almost capped so I put on the 2nd, but now it almost looks like the bees left.

I will be opening to check in about a week when I figure the goldenrod will be done. I guess that's the time I should use formic acid to treat for mites, once the honey is harvested? And, in doing this, do you cut open the plastic that the formic acid is in and just lay the entire thing on the top deep and leave for roughly 10 days, then start feeding 2:1 sugar water until it gets too cold?