Your temperatures are entirely nominal for that type of use. There is a critical layer of heatsink compound between the CPU and the heatsink, there was always the possibility that this had not been properly applied in the factory.
Skype and/or this plug-in seem to be at the root of your problem. My next step would be to see if there is a restore point dating back to before you installed this plug-in. If there is I would do the restore. If you haven't done it before click 'Start - Control panel - Recovery - Open system restore'. This brings up a panel listing the most recent restore points, if there isn't one there from before you installed the plug-in, click the button 'More restore points'. If you have an early enough restore point select it then click 'Start restore', accept the various warnings and let it run. It will probably do a re-boot, if it doesn't, do one yourself then see if the problem is fixed.
If it isn't, or you don't have an early enough restore, I would completely uninstall Skype and the plug-in through the control panel and, if necessary, use the Revo uninstaller to check that all remnants are gone before re-installing Skype if you want it - you don't quite make it clear whether it was Skype you don't want or just the plug-in. Revo is a very effective uninstaller, especially good at getting rid of the little components program uninstallers can leave behind. It's a free download and you can get it here -
Use the default settings and delete everything it suggests. Once you are certain it is gone try your computer and see if it is running normally - you can always re-install Skype later if you want it.