Creating web page now, want mobile app later. Best practices?

Question

I've been writing actionscript on and off for a long time now, but have always used the Flash IDE.  I'm hoping to build my next project using Flex Builder because I'm more of a code jockey than a designer.  I've got Flex Builder 3.
I'm involved with a modest mobile game project.  We're hoping to build a simple game and it seemed logical to do a quick-and-dirty version of the game in actionscript so the project members and a select audience might be able to evaluate the game dynamics in a browser before we spend a gazillion dollars building the game for iPhone and Android platforms.
It is my sincerest hope that I might develop my code in Actionscript and MXML and use this code to build mobile apps for iPhone, iPad, and Android without having to rewrite everything in Objective C or Java or whatever other language might be in play at the time we get it finished.
Q1: Is this possible?
Q2: Can anyone sketch out for me an overview of the process whereby one exports a Flex project to a mobile app platform?
Q3: Can any seasoned developers tell me the big "gotchas" to watch out for?  For instance, I'd hate to incorporate a component that would not export to one of the mobile platforms.
Any help would be greatly appreciated.

Answer 1

Thanks for your helpful post.  That's encouraging to know that I might be able to get the Flex 4.5 SDK without upgrading my IDE.  I'm a big fan of Eclipse and am considering trying to just use Eclipse with a Flex plugin. I certainly hope I might be able to download the latest eclipse and install a 4.5SDK plugin.  Might as well shoot straight for the latest SDK, right?  It would be great to avoid the $300 investment.
From your post, it sounds as though the Flex 4.5 sdk will be required for one to access the mobile phone features (gps, camera, accelerometer, etc.) which makes sense.  The ability to go actionscript->mobile was only recently announced.  Personally I think this capability is brilliant on Adobe's part.
I'm still wondering about the "best practices" aspect. Obviously the idea of a mouseover does not apply in the context of a touchscreen.  As I recall, the events exposed by Cocoa Touch (or other touch screen APIs/libraries) don't have the same Mouse/Pointer events as the AS3 that I know.  The point of this post (which is working well so far thanks for the input) is to try and make sure that I avoid building an app which uses features unavailable in a mobile context.  I'm starting to wonder if skipping the web page advice is being given because they mobile and web page paradigms are so different.
I still assert that the web page stage would be much easier to bring in testers -- meaning non-technical people who wouldn't know the first thing about installing an app on their phone. I'm talking about an audience of dozens or possibly hundreds and just can't provide them all guidance about getting the app installed.