Architecture for login in. Accessing Drupal serivces from a phonegap mobile app
You are right to be using services. 

I guess you've got this bit but i'll write it all the same: You need to obtain an anonymous user session via services and then use those details in the user login call.

Re the not being able to access across domains, its not jquery but actually the browser stopping this on your computer. But when you are using the webview component in your app it won't stop it. 

Sounds like you are on the right track, just crack as your main problem shouldnt occur :)

Edit: On reflection maybe that isnt totally helpfull

You could consider using Sencha Touch for this purpose. http://www.sencha.com/products/touch/

It kind of pitches itself as something you could use instead of native code, but ibuilt some pretty chunky ipad stuff on it and it begun to chug. Don't expect all transitions to be as smooth etc.

However, it does give you some great data/store tools

Sencha 2 is just about out
check the documentation for the rest proxy
http://docs.sencha.com/touch/2-0/#!/api/Ext.data.RestProxy

this would make handling lists and viewing content very easy

a good example from sencha 1.1 is http://dev.sencha.com/deploy/touch/examples/oreilly/ as it shows how you might extend a 'panel' to be a node view equivalent for the webapp. The syntax will be different in 2.0 but its a good way of thinking

I'm beginning to ramble now. Take a look and i'll dig out some code snippets if you choose it