What do you mean with "Initialise"? Is the simcard needed even to open the app itself? Then I guess it's a "drawback" Android version doesn't have, otherwise you wouldn't be able to use whatsapp on android emulators on a pc.

Just in case, What I meant on my post is the following:

1) You turn on the phone with simcard inserted.
2) You open whatsapp and register through sms or whatever you want.
3) You turn off the phone and remove simcard, then turn it on again.
4) Use whatsapp as usual, through wifi only, since 3g/2g/H/Gprs need the simcard.

Of course, doing this would allow you to use the simcard in another phone, while still using ONLY the first phone to use whatsapp. However, if what you say it's true, i don't see why it would need the simcard just to open the app.

I don't see it as a bug or something to fix, but as a fact.. if you have the app running on the background is because you're "online" at the time.

As you've been told, "Quit" the app when you won't use it, and the consumption will be gone, that's a exclusive feature wazapp provides.

It's not doing "nothing", it's open so you can get new messages, that's why you appear as online. If you quit the app, you won't get any messages until you open it again, at least that's how i see it, correct me if i'm wrong.