Maybe you can try only gamification techniques. A progress bar telling the user that their profile is 85% complete motivates they finishing completing their profile, right?
So why don't you just remind users how fast it is to use the website instead of going to the bank physically? Put a message when the user finishes a transaction telling how much time they spend to do so, like: "Congratulations. It took only 3 minutes from you to make this money transfer."
Also, there are safe ways to make comparisons between user scores. Show anonimous scores. And search for not so sensible data. For example: a user can score when they show a change in their behavior, decreasing their visits to the physical bank and increasing their access to the website, but you don't tell other users who this user is, neither where he/she is, what time, etc.
Have in mind that gamification is very powerful for motivating people to do what they already want to do. Save time is an example. But if they don't trust the website security, gamification won't help much.