The Trezor Suite (desktop/web app) is the interface you use to manage your crypto. The "login" connects this interface to your physical device. Your keys stay on the device.
No. A legitimate hardware wallet interface will **never** ask for your recovery seed. If you see this prompt, you are on a phishing site. Report Phishing
Firmware updates are done exclusively through the official Trezor Suite application with your device connected. Follow the on-screen instructions carefully. View Guide
A passphrase is an extra word (or sentence) that acts as a 25th word for your seed, creating a hidden wallet for extreme security. It's optional but highly recommended.
Yes, Trezor devices support mobile connectivity, typically via a physical cable (OTG) or Bluetooth, depending on the model. Check the official documentation.