forums.wsusoffline.net

Are there any minimum system requirements needed to use this program?

You need a computer running Windows for installation/Windows or Linux for download and an internet connection for download. Every OS/Office version, you want to download for will require about 1-3 GB free space on your drive. The Windows version, you want to install updates on, should not be modfied with software like nLite to prevent problems.

should not be modfied with software like nLite to prevent problems

does this include just slipstreaming updates?

No. It's primarily removing Windows components that are deemed "evil" (like Windows Scripting HOST/VBS Scripting) causing problems. WSUSOU relies on several components that are often removed by clueless users.