Windows 7 OEM, new motherboard and CPU. For that change, a new OS install is generally recommended or required.
Windows 7 OEM and new motherboard - Your OEM license is invalid. However...Microsoft may authorize reactivation with the new hardware. They are under no obligation to do so, though.
With a new OS installation, that is a new Registry. It knows nothing about your applications from the other install. And there is nothing that I know of that can reach in, find the proper keys and settings, and apply those keys/settings to a new Registry.
Some applications can possibly be just copied over, but the majority will not work doing that.
1,000 applications? Really? This is when you consider putting an installation with most of that in a VM, and running it as a guest OS.