Hi Oldsalt!
I've experienced your problem before.
First: I've used 7z to uzip all files and it is not needed that you use a temporary folder. You can extract them directly into IL2 root folder.
Once you've downloaded the file you want to extract, right click on it and a menu will appear (I'm using Windows 10):

Sorry, my 7z version is in Spanish, but I suppose the menu list is more or less the same in English. You must choose "7-Zip > Extract here..."
Then, a new window will appear, and you can extract in the root CUP IL2 folder:

In the section "Extract to [Extraer a:]" (and a small square with three dots), you can look where your CUP folder is.
In "Folder mode [Modo de directorio]" I've always used "Complete folder [Directorio completo]", as shown in the picture.
In "Overwrite [Sobreescribir]" you can select "No confirmation [Sin confirmación]".
I've done this for the complete installation, and I've never found any problems.
Second: I would recommend to do the Restore Point, at least the last one for each module you have installed. I think they are intended to have the latest version for each DOF, WAW, JTW and TGA modules, and get rid of old and useless files.
Third: Everytime I have completely re-installed DOF, WAW or JTW modules, I have lost the link for TGA (Golden Age) module in the IL-2 selector. I suspect the explanation is that TGA module was added much later than DOF, WAW and JTW. Probably the first files that you install of these three modules affect the options available in IL-2 selector and remove the TGA option. A rough but effective solution is to install TGA module at the end, after installing any other. Once you have installed again TGA files, the 'Golden Age' will appear again in IL-2 selector.
You can update DOF, WAW and JTW without damaging the options in IL-2 selector. I think TGA is only lost when you install the other modules from the beginning, just if you have TGA previously installed.
Sorry if my English is a bit confusing. I hope this helps.