A Visa Electron card is similar to a Visa Debit card (i.e. you can only access funds that are in your bank account), but quite a lot of retailers don't accept them.

As for submitting to the Ovi Store, I think there are only a few requirements that you need to have in mind:

1. Must have an 'About' screen with application name, version and developer info.

2. Must be 'single-instance' (i.e. you can not allow more than one instance of the application to be launched). This is met automatically with the latest version of the Qt SDK.

3. Settings should be saved when the application is minimized. I don't think this is a strict requirement, but it's easy to do.

You can use Javispedro's icon generator to create the Harmattan icon.

What are the QML problems that you're facing?