Support will have to chime in about the push notifications.
As for making updates to the app depending what you need to update you have several options.
Here is one: http://www.genuitec.com/support-genuitec/viewtopic.php?f=14&t=5716&hilit=fallback
Using the same concept you can change just about anything, especially if you use local storage for information. Juts initially read the data from local storage (if its empty load some default info. Then you can use the ajax load to read a text file into local storage to update.
RSS feeds are another great way to update without having to resubmit your app.
I use the above sample on several apps to keep vital info up to date.