14 or 21 day railpass to buy?

Hello,
Can you please help me to decide.
With my itinerary here below, should I get a 14 or 21 day Rail Pass?
I understand that I can use the Rail Pass to Narita Airport to hotel and vice versa. Correct?
Can I order a WiFi Dongel from you ?
Do you offer immediate Wats App Assistance when I am stuck?
My itinerary:
Narita Airport to Hotel
Tokyo 2-4 tot 3-4(1 night)
Kyoto 3-4 tot 7-4(4 nights)
Kurashiki 7-4 tot 8-4(1 night)
Naoshima 8-4 tot 10-4 (2 nights)
Hiroshima 10-4 tot 12-4(2 nights)
Osaka 12-4 tot 13-4(1 night)
Kiso Valley 13-4 tot 14-4 (1 night)
Yudanaka 14-4 tot 16-4( 2 nights)
Tokyo 16-4 tot 19-4 (3 nights)
19-4-18- Hotel to Narita