Extra password \ PIN requirement when editing anything in the "Recovery" and "Security and Privacy" tabs.
I'm just in general paranoid about security after my previous gmail account was compromised.
I feel like the recovery and security tabs are most vulnerable. If users could make a custom pin or password that is different from the standard email password or mailbox password. I would feel more comfortable, I wouldn't want someone to somehow gain access to my inbox then change the recovery or password \ phone number etc or delete \ remove the recovery keys.
I also feel a bit at unease with the app, because the app does not give an option to change a password, so getting a login notification from an unknown device on my mobile does not really help if I can't sign anyone else out or change the password if I don't have access to a PC.