Advice on investing for non residence

Hi, wise ppl on this group, really appreciate if I can receive advices from you guys.

I am applying for PR visa and my husband is Japanese. My husband doing remote job for japanese companies, he is a freelancer, not seishain. Nenshu about 700- above 1000man depends on years.

Things here is the tax for freelancer is ridiculous, he usually paid 200-250man a year for: personal tax, residence tax, insurance tax etc. We plan to move back to my country and cut the address (juminhyo) and live for a while to avoid tax asmsp. He will still working for the same company and receive salary through the same bank.

We also dont want to pay any tax in my country (mostly personal tax). We r investing on Nisa and online Tanaka gold (buy and keep the gold online).

1. Anyone knows tips/platform to investing money when you oversea in japan? (non residence)

2. Can he keep buying gold even if cutting juminhyo?

If cutting the juminhyo and sell gold immediately (profit over 50man) do he needs to pay tax for the profit? because technically he is non residence at that time.

I want to keep some money in Japan and invest, some money will send to my country for living expenses.

We are early 30s and barely have assets or money, hope to hear from you guys.