Anybody who wants to live in Monaco should apply for a permit through the French Embassy unless you are a EU Citizen.
You must prove that you have a clean judicial record, show a
lease or that you own a property in Monaco and pass a medical visit.Also you must show a declaration from an Monaco Bank that you
have sufficient funds in your account.Usually EU100'00 will do.
Of course you dont need to keep these funds all the time.Once you have the declaration from the banks you can withdraw the funds.
However every year for the first 5 years you will have to show a declaration from your bank so you have to put back sufficient funds in you account. Also you have to stay al least 183 days per year. Monaco beeing a small city you have to be there so you can
show the autorities that you aprticipate in the social life. You can rent a small flat 80 sq meters for ard 2500n3000 euro. It will take about 3to 4 mths to get your permit.Once you are settle you can trade and do what ever private business tax in Monaco is zer

f course you can have an another residence in Europe and switch back and fourth. Do your trade and enjoy your life.