How many days in advance is advisable to book these buses? For shirakawa-go and kamikochi daytrips in October. Thank you

I did but bank said it's not their side problem. Anyway I used a Taiwan credit card all is good hehe. Got my tix.

Yes. I hate to tell u this, but I told u so.
Some more u so skeptical say is bank issue

What kind of daily/weekly pass can be used for all trains in Osaka, Kyoto and Tokyo which worth the price? Planning maybe 3 days Osaka, 4 days Kyoto, 2 days Fuji and 3 days Tokyo...

Can register, but ur credit card dont know whether can go thru or not. Good luck! Cause i registered as well but credit card tak boleh make payment

I buy the ticket to kawaguchiko. Not part. I didnt buy jr pass because for me not worth it

I dunno why you guys so obsessed on seat resevation. Most people here are not going to Japan during Golden Week. Even you going on Golden Week, due to JR dirty trick, you also won't get a seat.

I been To Japan so many times, entire Forumer here combine also can't more than me. I never ever once in my whole life sit on full passenger train (Limited Express
& Shinkansen) except Golden Week.  Even Airport Express (NEX, Keisei Skyliner, Haruka , Nankai) more than 300 times, not even once full. 

Even the most popular Kintetsu Shimakaze & Hinotori also never ever full.

You guys here really kanasai......

citibank clear card

Kansai Amazing Pass is only for 3 days? So that means I have to buy 2 times if I am staying about 7 days in Osaka and Kyoto? Metro can probably cover Tokyo.

I am planning to touch down Tokyo first..then take train to Kawaguchiko, then bus to Kyoto and finally goes back to Malaysia from Osaka.

I usually go to the one near Nagoya Station. post their FB below.

https://www.facebook.com/pages/Hitsumabushi...67574336588079/
They are located at ESCA underground shopping.

It's not Inou.  It's Bincho, they have a few in Nagoya. The one I went is walking distance from Nagoya Station and it's underground called ESCA underground shopping

Google map will guide you to the stairs leading down to ESCA underground shopping but will not point you to the exact shop. need to walk around and find base on picture in google map

Either Hitsumabushi Bincho or Maruya, both also taste average as my standard. 1st timer, maybe......but for old timer, I won't recommended.

Nagoya people like thick miso paste. Everthing in Nagoya sauce will be very strong & thick which really over coverd the original taste.
Plus Nagoya eel eating way called Hitsumabushi style.
https://hitsumabushi.co.jp/en/hitsumabushi/
Nagoya people like it, some people like it, but not me.

Plus I already been whole Japan, I tasted so many thing, so many restraurant. I know where can get even more tastier eel. 

Since you going with children. You won't able to taste it. 
Either one day you going alone / 10 years later 
Then I will tell you.  But the price really insane high.

BTW, today I lepak at Pavillion. I was so surprise, I found one of my favorite restraurant in Japan, Yayoi !!
Overall got surprise & disappoint. Surprise part was the price are exactly 1:1 to Yen. One set meal approx. 1000 - 1300 Yen & Malaysia are Rm40-60
Disappoint part are halal. Oh man......Japanese & halal are biggest enemy.  Yayoi most famous , crowd jewel Trio Meat set are not available in Malaysia because of pork. 
No serving alcohol 

One of reason was:
No Chinese tourist.

oh,  I wil buy the round-trip ticket for the the Nohi Bus from Takayama to Hirayu Onsen/Kamikochi, so I suppose this one can

Cant find details about this ticket elsewhere apart from here:
https://www.nouhibus.co.jp/route_bus/kamikochi-line-en/

Takayama～Hirayu Onsen～Kamikochi Round trip set ticket

The one combined with Shinhotaka ropeway can be purchased from Klook

Nohi bus Kamikochi route only can reserved seat through Telephone.  Either you called using IDD or brought ticket at Nohi Bus center.

English speaking customer service ...No idea, because I always get ticket one day early at Takayama HQ.

April, most of people will choose Alpine route over Kamikochi.
But in July - August will be busy because summer hikers going nearby peak hiking.
October will be Kamikochi highest peak due to autumn season. Golden red leaf everywhere. Most beautiful scenic season.

Both also beautiful but Myokin got more like Jiuzhai Valley feel and that make it extra special.

Start from Kamikochi Bus Terminal > Taisho Bridge > Kappa bridge > Myokin Pond > Myokin Bridge > Kappa bridge (Another side) > Taisho Pond > walk on main road to Teikoku Hotel
This route x 3 times in Summer & Autumn & Winter.

Kamikochi area food are crap. Bring alot food & beverage from Takayama to Kamikochi.