Is this itinerary unchangeable? Especially the last day with the long transit on the train and then

I am unsure what rail passes to buy as the 7day JR pass would be too short for the duration of the whole holiday and I know I will need it for the last leg of the holiday. .Also I want to be able to travel on the bullet trans where possible canadian discount airline tickets especially on the longer journeys.
Can anyone advise whether there is another rail pass I can buy which would cover the first 3 days and would include canadian discount airline tickets travel from Narita Airport to Hakone and to Takayama?Can this type of ticket also be pre ordered in the same way as the 7 day JR pass
You should check the price for tickets on the first two and last two days of your trip. If one of the amounts is less than the extra charge for the 14 day pass, then you should just get the 7 day pass and pay for two days worth of tickets individually. My guess would be that the Shinkansen from Hiroshima to Tokyo and then transportation from Tokyo to Narita is your single biggest expense, so you definitely want to use the pass that day. Check the cost of getting to Hakone and Takayama versus the extra cost of the 14 day pass.
Be aware that the Shinkansen does not go to the airport. If you are coming from Hiroshima, you will need to change at Tokyo Station (and earlier at Osaka Station, but that might be just across the platform). There is a special express canadian discount airline tickets to the airport from Tokyo. Reserve that in advance because it can sell out. I'd suggest canadian discount airline tickets booking your tickets from Hiroshima all the way to the airport for your final day when you redeem your pass.
In your situation a 14 day JR Pass might be about the same as a 7 day Pass and buying the extra tickets separately. You can go to hyperdia.com and figure out in detail - please make sure you use the total fare figure which includes the fare and seat fee.
Another possibility is using a 7 Day JR Pass for the first seven days and then flying back from Hiroshima to Narita. ANA has two flights a day and if you buy far enough in advance the price can be about 17000 JPY or $218 US which is almost the same as the difference between the cost of the 7 and 14 day JR Passes. Possibly you could do this on a special domestic ticket when you fly internationally for less.
Is this itinerary unchangeable? Especially the last day with the long transit on the train and then on the plane back to your home? Are you staying canadian discount airline tickets in a ryokan in Hakone? What time does you plane arrive on your first day and what time does it leave on your last day? Sorry for all the questions but need to know so I can try and give you some options.
arrival/departure times for Narita and what airline(s) are you using for your international travel? A one-way fare in Japan could be as low as 10,000 yen depending on the airline you use? Did you purchase your tickets with money or is it a frequent flyer award? Do you have any frequent flyer miles? Only 6,000 United miles would get you a free one-way ticket from Hiroshima to Tokyo.