I don't think Nippori is a sensible choice.

My choice, on balance, would be to transfer at Ueno. Once you've emerged from Shinkansen (deep subway at Ueno) you may as well walk to the Keisei Ueno station. There are escalators for all significant climbs and descents.

Another option would be to take the Shinkansen to Tokyo station and get the Narita Express from there. With that option it's all JR (so you can use a JR pass if you have one). The transfer is from the elevated Shinkansen tracks to the deep basement tracks.

A third option is to fly from Komatsu Airport (near Kanazawa) to Narita with ANA. Depending on your time of departure, this might be an attractive option.