Thank you very much Pete for still trying to help me out.
In the meantime I've learned a bit more about it. As I could see after doing a search in winsxs, SimConnect consists of 3 files: the dll and an additional cat and manifest file. Only the dll resides in the folder within the winsxs directory, the other two files resides in the winsxs directory itself. But I only deleted the three folders, so I guess since the other files (total of six files, regarding to each folders name) were still there, the installer didn't do anything.
I still got the first two folders in my trashcan, the third one I could recover from a shadow file. Now the challenge was to move those three folders each containing one dll back to winsxs. As long as the user "TrustedInstaller" is the owner of winsxs, there is not really much you can do, because you can not give yourself the necessary rights.
So I changed the owner typing the following in a admin cmd box: takeown /F winsxs
After that I typed: icacls winsxs /grant "Flying Eddie:F" to give full access myself.
I verified that TrustedInstaller has still full access though. I could use the GUI to grant full access myself for the three folders. Now I was able to simple move the three folders back into winsxs.
What can I say, FSX works as before, not better but it works. I think the most important thing about micro stutters is to keep the hd defragemted anyway, especially when using tools like UT2 with heavy loads.
Only one thing is left. I could not change the owner of winsxs back to TrustedInstaller. You cannot select this user when using the GUI to change the owner. I've not yet figured a command to use for this task. Unfortunately there is no "See Also" in the help text of commands like with UNIX.
Maybe I should just leave it like that as long as it works.
Thank you very much for your kind help.
Regards
Eddie