I am getting an error installing the latest version. It seems that the first installation failed with an Add-In-manager error similar the the "80070002" experienced by someone else. Then I tried to reinstall the version and got a .Net Framework Installation Utility error with the following error

EventType : clr20r3     P1 : installutil.exe     P2 : 2.0.50727.1433    
P3 : 471ebfbb     P4 : mscorlib     P5 : 2.0.0.0     P6 : 471ebc5b     P7 : 1295
P8 : 14     P9 : system.io.filenotfoundexception 

Everthing is stuck now?

Removing the folders shouldn't have made a difference unless there were some type of permission issue...but I am glad you got it working!

Nope.  The only thing that you would have to take into account is if the next update is not pre-compiled for 8.1.  Other than that...nothing to worry about!