Will I have to go to the Tobu Sightseeing centre to validate it or will I be able to simply print everything online and just proceed to the Asakusa TobuLine station?

I am worried because I am coming from Ito and arrive Asakusa 12.06pm. The train I need to get on leaves for Nikko at 12.30pm.

It may be quite a rush if I have to validate the Pass or collect the tickets at Asakusa.

Would be great if I can just print everything online and proceed to catch the train.

I just went ahead and purchased the All Nikko Pass online, and found out the answer to one of your questions. It looks like we'll have to print out our purchase, and exchange for actual tickets at Asakusa. Here's exactly what it said when I completed the purchase:
"This confirmation page is an important identification document for you. You can exchange this document for your pass at the Pass Booth on the day of your trip. So please print out two sheets of this page and be sure to keep them. "

Thanks for letting me know. I have decided to buy the JR East Pass and take the shinkansen route to JR Nikko instead.

This is hassle free and I can perhaps take the opportunity to ride the shinkansen to yamagata after nikko. Its a Flexi 4 day Pass Y20,000 allowing any 4 days within a month. I can use the Pass for my 10 day visit in Japan.

We are coming from Ito so I dont want to worry and rush or miss the trains at Asakusa esp when I cant read Japanese nor speak the language.

The Tobu option is fine provided one has time to search out the Asakusa station in time.

Thanks once again. Do enjoy your trip.