Car rental from Kawaguchiko to Kanazawa

Hello,

This is my first time travelling to Japan and i was hoping if somone can share some insight on car rental experience in Japan.

I want to visit Fuji five lakes for couple days and also Kanazawa for another couple of days. My initial plan was to take a train/bus from Tokyo to Fujikawago and return to tokyo after 2 days and take another train to Kanazawa. And from Kanazawa take a day trip to Shirakawago and Tokayama. But this looks as if i will be spending too much time in travelling.

I realized that there is a Toyoto car rental close to Fujikawago station where i can pick up the car and use to go around Fuji lakes ( even the ones which are not so well connected by public transport) and drive to Kanazawa after 2 days stopping at Shirakawago and Tokayama. And if there are cherry blossoms in Matsumoto castle, we can also go there. ( i will be around these places from April 16- April 20)

I had a few questions hopefully someone can answer
1. Does that sound like a good plan?
2. I think i will have to be driving through the Japanese Alps, Is the driving easy there?
3. While booking in toyota rental car , its asking if i need an ETC, i thought it comes as a default option for all the cars, and how do i top up that card? Or do i pay it at the end of the trip?
4. I have a british driving icence, i can get a IDP which will most likely be in English, does it need to be translated in Japanese?

Thanks

For my previous visits to Matusmoto Castle, I think mid-April is way too late. I have been there in February and March (different trips) and enjoyed the blossom (probably plum rather than cherry outside the castle grounds).

2. I think i will have to be driving through the Japanese Alps, Is the driving easy there?

I'm glad to know that you're used to driving on the left side of the road, but I wonder if you're familiar with curvy hills. Do you know how to "pump" the brake pedal instead of keep stepping on it? How about driving in rain or darkness? If you're not concerned about things like that, than what you get is what you see on Google Street View.