Tohoku - Please review my trip

Dear Japan Guide Community,

i intent to go next year to Tohoku and have planned some spots which i want to visit and i would glady receive some feedback from you.

Please check this map:
https://drive.google.com/open?id=1bDqWMhiCT5YeQyTL34X8YyqTdkU&usp=shar...

remarks:
* i will probably start in Sendai and return from Aomori. (which connection flights from / to tokyo)
* I have marked all kinda spots which might be interesting, i assume it will not be possible to visit them all, so for that reason not all of them are on the driving routes
* below the points of interests i added some layer for each day, including the things that i want to see on these days

so my requests and questions to you:
* do you think the general route is ok or would you drive somehow else?

* which time you think is the best for the route?
** I intend to go on august, since it seems to be the best time for dewa sanzan - is it ok?
** all other points seem not to be season critical, since i will not go in winter (but i could go july-november)

* related to the above question: do you think it is better to make the route from north to south or like i planed from south to north? or does it not make much difference, since it is anyhow only 2 weeks

* do you think some of the days are too "empty" or would you add / remove / combine some and spend the time on something else?
** generally i rather be a slow pace traveller, enjoying sceneries, rather than rushing from one place to another

* do you maybe have some other points of interests which you recommend and i am missing?
** i am interested in all kind of stuff, especially
*** architecture (also modern ones),
*** art / museums,
*** food (i would drive very far for good, special food) and
*** (most important:) onsen.

* i assume this route is only do-able by rental-car?
** or do you think i can also make this with public transports? (which i would prefer, but as far as i saw especially in the Hachimantai area i will get problems?)
** should i drive back from Aomori to Sendai? according to google it takes 4 hours per car, which doesnt seem to be so horrible... if possible i would only go one way, but i heard it is very expensive to leave the car in another city, than the one where you rented it. or this this not the case?

Also any other feedback welcome. Thank you very much!!!

btw, i additionally wanted to ask: is the point, which is marked as number 8 (“’“aŽR‘�–{Ž›‘å“ú–V), the temple where you can see some of the mummies from Yudonosan? or did i got the wrong temple?

On the Buddhist mummies (sokushinbutsu ‘¦�g•§), yes, Dainichibo is one of the temples where you can see one. Tsuruoka has 4 of them. The others are Churenji Temple, Honmyoji Temple, and Nangakuji Temple. Here is a map of all of Yamagata Prefecture's sokushinbutsu:
http://sp.yamagatakanko.com/log/?l=348168

ok, i might have had too many questions, i think i got all the main sights and onsen meantime,
but please maybe someone could help me with the climate and route-order question:

i am flexible with time, so i can start the holiday whenever i want. there are two things which seem to determine the time range:
* walking up gassan on dewa sanzan, which seem only to be possible in july - august
* seeing one of those many matsuris (e.g. in akita or aormori), which seem to be in the first august week.

the whole route seems to take about 16 days.
route is here:
https://drive.google.com/open?id=1bDqWMhiCT5YeQyTL34X8YyqTdkU&usp=shar...

=========
the main question is now:
=========
should i start in middle of july from sendai and make my way up to akita and aomori, so i will reach them during the matsuri time
OR
should i fly to akita in first week of august and make my way down till sendai, doing the dewa sanzan in the end of august
?

what do you think will be better regarding weather and climate?

remarks:
* i would prefer the first variant if possible due to better order of events (more walks in the beginning and later more city-comfort)
* i read all kind of climate tables, most of them say for tohoku even july is fine to go (compared to the rest of japan) but it will rain more than in other months. will this rains be full day long or just short rain durations, which would not bother so much.

thanks you in advance!

I think those are all details that won't really make any difference. Also I don't drive, so can't comment on that.

If you really want to Self drive in Tohoku,then I will recommend you to buy:Tohoku Expressway Pass: 14 Days=12000‰~.This amount is not a big burden but affordable to pay.This pass will give you great benefit,So A foreigner with little Japanese knowledge and How much yen needed to pay in Toll plaza everytime you drive in Highway and Expressway,is not a big concern. I also recommend you to buy Sendai area pass 1 Day cost=1300‰~ cover143 km of JR network+Bus+ subway+ non JR railway.Normal 1 way JR cost 2420‰~.By this pass,you can travel All lines of Sendai Airport Access ,All lines of Loople Sendai, Sendai City Buses and the Sendai Subway,Miyagi Kotsu Bus between Sendai Station and Akiu Otaki.,Abukuma Express Line between Tsukinoki and Abukuma station.

Thank you very much Ron!!!
I already knew about Tohoku Expressway Pass and intended to buy one. -
But I didnt know about the Sendai area pass! This is great, cause i had in mind to see Sendai on the first two days and only afterwards rent the car, so this will help me to save a lot!
Thank you again!

btw: since i travel with architects, does anyone of you know some modern architecture must-sees which are on the route and not mentioned yet? (i tried to google all, but for sure have missed something)

They like buildings from Tadao Ando, Toyo Ito, Kazuyo Sejima, Kengo Kuma and such...

For architecture check out this page:

http://www.worldarchitecturemap.org/

An architect friend did recommend it.

Enjoy your trip to Japan!