When I used mullvad it seemed like a high quality vpn, the feature of blocking all computer traffic untill vpn is connected seems necessary, why dosent express have this? is there a way to enable it? I feel like im naked when im sitting on my computer before connecting with my normal IP vunerable. Can anyone help?

ExpressVPN gives you that great feature too. Just click on the the menu in your ExpressVPN window , under the "General" tab and select "Stop all internet traffic if the VPN disconnects unexpectedly"

Yes but that dosent block the internet traffic before your vpn connects