For a three weeks stay on a 60 days visa exemption there’s no issues to re-enter Thailand and get another visa exemption at the border/airport. You just fill out a new TDAC.
If you really entered Thailand on a 60 days tourist VISA you applied for online as a e-visa and payed around 40 USD before you entered Thailand, you’ll need to purchase a re-entry permit in order to get stamped back in again.
Yes you’ll have to report after 90 consecutive days anyway, you won’t get any trouble at the airport but you might and probably will be fined at the immigration next time you register.
With Italian passports you’ll normally get a 60 days visa exemption and free stamp upon arrival which can be extended with additional 30 days at your local immigration.
Almost impossible to open bank accounts now. You’ll probably have to contact one of the bigger visa agencies in Bangkok who still are able to open and provide this service as a part of a total visa package or apply through an embassy at a nearby destination with your bank at home.
You’ll just get a No Show at check-in and the trip will be cancelled and maybe a lucky fellow will get a free upgrade to business if the flight is overbooked.
has confirmed they’re still able to assist you with a bank account if you’re on visa exemption or tourist visa and apply for a Non O in country with them as a total service. I know a couple of other too.