Nikko and Ashikaga Flower Park Logistics

I'm thinking of going to Nikko and Ashikaga Flower park in my next Tokyo trip. Maybe stay 2 nights?
How hard would it be to get between the Nikko shrines and the flower park on public transport preferably trains?
Would it be easier to be based in Nikko or Ashikaga? And can we go straight to Narita airport from there or would be easier to go back for a few more days in Tokyo?

Appreciate any advice or insights.

Thank you!!

How hard would it be to get between the Nikko shrines and the flower park on public transport preferably trains?

Take Tobu Railway from Tobu-Nikko to Tochigi Station and transfer to the JR Ryomo Line. Get off at Tomita which is a short walk from the flower park:
http://www.hyperdia.com/

Would it be easier to be based in Nikko or Ashikaga?

Not sure about the easier, but Nikko is definitely the more interesting base.

And can we go straight to Narita airport from there or would be easier to go back for a few more days in Tokyo?

Ashikaga is slightly closer to Tokyo than Nikko, but not considerably.

THank you.