Should I include Takayama or not?

I am trying to plan my first trip to Japan from March,27 to Apr 12 next year.
Below is my current plan. However, I am still not sure if I should include Takayama and ShirakawaGo into my plan, because first, it is a long ride from Tokyo, and second it seems like it will be cold in there. I can not decide if it still worth the efforts in a cold weather, or I should change the plan and see something else instead. What do you suggest? Any other suggestions on my itinerary will be really appreciated also! Thank you in advance!

Day 1,2,3 – Tokyo (this includes the arrival day)
Day 4 – Nikko (Overnight???)
Day 5 – to Takayama (overnight Takayama)
Day 6 – Takayama (day trip to Shirakawa Go???)(overnight Takayama)
Day 7 – to Kyoto (overnight Kyoto)
Day 8,9 –Kyoto (overnight Kyoto)
Day, 10 – Kyoto, day trip to Nara(overnight Kyoto)
Day, 11 – to Koyasan overnight
Day 12 - to Kurashiki with the stop in Himeji (overnight Kurashiki)
Day 13 - Kurashiki/Okinawa (overnight Kyoto)
Day, 14 Miyajima island overnight
Day 15 Osaka (want to try the SPA world)(overnight Osaka)
Day 16 Departure from Osaka

I assume that Okinawa on day 13 is supposed to read Okayama.

The itinerary is packed. Dropping one or two destinations would give you more room to breath.

Then again, if you like packed itineraries and fast travel pace, it can be done.

I would not worry too much about the cold. It is not that cold (double digits likely during daytime, only slightly below freezing possible during the nights). Not much snow remaining in Shirakawago. Even less in Takayama. Maybe none.

Last year I travelled to Shirakawa go and stayed in a farm house. It was one of the highlights of my trip, and well worth the journey through the Alps from Takayama to Shirakawa go and then on to Kanazawa.Staying overnight in each place.If you wish to see more of the countryside and Alps I highly recommend the journey. It is a spectacular part of Japan and you see the historic parts of Takayama as well. The bus travels onto Kanazawa, which is also worth the trip also.
You could do a day trip to Nikko from Tyoko, However, don't miss Nikko. Have a good trip- it is never long enough, I am returning again this year!

Uji, thank you for your response! Yes, I meant Okayama :) Actually, I used Frommers and this site suggested iteneries to create mine. Mine almost exactly match the one suggested by this site, so I thought it was reasonable. What would you drop? Would you drop Takayama or something else?

Again, if you like a fast pace, I think it is okay. If you want to slow down a little, I recommend to drop the place that sounds least interesting to you personally.

I personally think that Frommers is overrating Kurashiki (at least in their guide book version five years ago).

Thank you, Elly! Thank you Uji, again! OK, then Takayama is in.
I think if I drop Kurashiki, then I can stay one night in Kanazava and go to Kyoto from there. Is this a better idea? It is very hard to decide what personally appeals to me, because I only can rely on book descriptions and some photos. I would love to see old Japan and the country side.

From Takayama you can catch a bus which will take you to Shirikawa-go. Ogimachi, (across the swing bridge) is a wonderful place to stay if you get the chance. we stayed in one of the Gassho-zukuri farm houses. This was a fantastic experience.
We caught the bus onto Kanazawa the next day. From Kanazawa it is easy to catch the train onto Kyoto. We had our suit cases sent from our hotel in Toyko to Kyoto. I think it cost about $50 Aust per bag, but well worth it. We took our day packs for the three nights in the mountains. Our bags were saftly waiting for us in Kyoto. Our Travel agent in Sydney arranged this prior to leaving.
In Kanazawa, we bought a day ticket on the tourist circuit bus, It will take you to the more popular sites such as the Kenrokuen Park gardens. As I mentioned before, this was one of the highlights of the trip- I hope you get the chance to experience it. Elly

Thank you,Elly!