The validation wizard will do some testing with the Edge server. If you want to do client testing there you can put a user on the internet and make sure they can IM with internal users, download the address book, and initiate a Live Meeting session. When you test Live Meeting make sure you test uploading content (such as a ppt or doc file), app sharing, and whiteboarding. If you can successfully run all three of those then you know it's working as expected.