Try this (for many of the failed updates)
Open programs and features. Select any (or all, eventually) of the Net framework programs and select repair. Reboot and see if you can run the updates for that particular feature.
One way is to Rename the SoftwareDistribution folder in the Windows directory. This forces the system to rebuild the database and hopefully correct the problems.
But since I am not sure the database is your problem, perhaps you might send me another file before trying a database rebuild. This one is in the Windows\logs\CBS folder and is called CBS.log and it will be large also. This file shows other information and might give a clue into why the updates are not being recognized.
While you are doing that, could you check the status of the update I mentioned earlier that is not being recognized? Maybe it will tell us if some updates are actually installed or not.
Maybe we should go back to the problem you are having with the Update Readiness Tool.
It appears, after you downloaded the file and double click it, you get a message about what program to use. This is abnormal just by itself. If you could get it to run, it might fix your other problems.
So, on the desktop, hold the shift key and right click. Select "Open command window here" from the context menu (this will not be an administrative window).
Type wusa /? and hit enter. A separate window should open with the switch optons for the command.
If another window does not open or you get some type of message, then do a search of your system for wusa.exe and there should be 8 entries with 4 having an additional .mui extension (x64 system).
If you don't have one in the Windows\system32 and possibly the Windows\sysWOW64 folders, we need to get those back.
This is a Microsoft website that describes how the installer works, but don't worry about expanding any updates to a temp folder as it mentions.