Exactly the same way as ESP-01, additionally connect GPIO15 to ground. Yes, you're right, the ESP8266 is not 5V tolerant, and for 5V arduino boards level shifter or divider is required.
In particular case the USB-Serial converter has TTL (3.3V) level output, so such connection is safe.
Exactly the same way as ESP
Exactly the same way as ESP-01, additionally connect GPIO15 to ground. Yes, you're right, the ESP8266 is not 5V tolerant, and for 5V arduino boards level shifter or divider is required.
In particular case the USB-Serial converter has TTL (3.3V) level output, so such connection is safe.