Public wifi. How secure is a VPN?

Question

VPN

Can they intercept data and find out my logins/passwords in the following situations?
Situation 1. Public unencrypted unpassworded WiFi. I connect to the bank-client via https.
Situation 2. Public unencrypted unpassworded WiFi. I connect to the bank-client via https via VPN.
Situation 3. Public unencrypted unpassworded WiFi. I connect to the bank-client via http via VPN.
When using VPN and http, is the data only encrypted from the VPN to the site? Or are they also encrypted from my device to the WiFi router? Does a VPN solve all the security problems on public WiFi, and if not, what problems remain and how to solve them?

Answer 1

(1) you can replace the certificate with xs which client on the mobile

Do you know the client-banks where this is possible? Surreal situation.
At a minimum, protection against man-in-the-middle attacks.
If the VPN is connected on your device, then on the Wi-Fi router your traffic will already be encrypted.
Decides if it's not PPTP, of course. Use OpenVPN/L2TP/IKEv2 if the task is to protect traffic.

Answer 2

2) 3) more reliable, with (1) you can replace the certificate with whatever client on the mobile
encrypts from the device to the VPN server