I think we will need a bit more information to properly help you out. What your climate is like will help with what you will need for them.
I will hit on the items you listed as best as I can with the thought that you may have cold windy winters.
Solid floor for the coop? I would say yes for many reasons. If you are building an elevated coop then things cannot reach up into the coop to grab a chicken leg and the wind cannot blow up the skirts chilling the chickens. If you are building it on the ground then so long as the coop area is in a very dry part of the yard you can do a dirt floor and deep litter method of maintaining it.
There are a lot of good threads about deep litter on this site.
How to attach chicken wire to the run...... Well chicken wire is designed to keep chickens in it will not keep predators out. You should invest in 1/2x 1/2 inch hardware cloth. It costs more but then so do replacement chickens. To attach use screws with fender washers or use a heavy duty or air stapler then cover with strips of wood held on with screws. This will give you the security of knowing the wire will not be able to be pulled off.
For the roosts a 2x4 with the 4 inch side upward will allow them to cover their toes in the winter and help prevent frostbite.
Have you researched in the learning center about ventilation needs of chickens??? It is very very important they have fresh air and not a draft in the winter.
TONS of great info here.
https://www.backyardchickens.com/atype/1/Learning_Center
Best wishes and ask lots of questions. There are great people on here that will help you with whatever they can.