1. I prefer digital since can complete everything back at home and faster to go through immi and custom. This only apply to inbound, outbound no need.

2. For tax free again can use the visit japan web to register all your info and will give qr code for you too like immi and custom. If not mistaken now tax free will need to be done in airport rather than individual shop starting 2025 cause a lot of c country ppl abuse the system. But im not sure accurate or not.

3. For tokyo most of the place accept cashless like cc, suica. But some places like ramen shop only accept cash so better take some. If need extra cash can just withdraw from 7/11 atm. No need paypay, afaik pay pay need japan phone no to register.

4. You can only choose one physical or on iphone. Once linked, the physical no longer can use.

Paypay can just use TouchNGo app lah

Since you just travelling alone, i suggest to just stay in business hotel like toyoko / sotetsu inn to save some money. The extra money can spend on food 

https://unseen-japan.com/hokkaido-biei-tree...ngry%20farmers).

Trees in Biei to be cut down

https://unseen-japan.com/hokkaido-biei-tree...ngry%20farmers).

Trees in Biei to be cut down