Trying to script complex web forms with Javascript?

Hello, and thanks for this great place to ask Applescript questions. I am currently trying to script a web browser to do my bidding, since there is no other way to do the scheduling I need. I looked at a very helpful post (http://macscripter.net/viewtopic.php?id=22412) which gave me some good ideas, but

So basically, I’m trying to use Postling to schedule posts, but unfortunately the Postling web interface (like Facebook and other Web 2.0-ish sites) is highly resistent to being easily scripted. There is dynamic HTML that changes the on-screen appearance when you click a link, and I need to accurately simulate this clinking (preferably not with UI scripting which never works more than 85% of the time). If there’s a way to make Javascript work with the page that would be best.

On screen examples are here. Screen one http://twitpic.com/9akyr1 changes to http://twitpic.com/9akz5v when Upload a Link, Schedule for Later and the J-List Facebook checkbox are physically clicked.

So basically what I currently manually do is

Click Schedule for Later to make the schedule part appear
Click the Tumblr box
Click the Facebook box in such a way that it loads the album list I need then
Set the value for the album pull down (Wall Photos).

I got Javascript to correctly check the checkboxes for me, e.g. the Facebook one, but sadly it doesn’t trigger the list of Facebook albums that I need. I was doing the Facebook dropdown part by tabbing into those fields, but the developer just changed the layout again, breaking this.

I currently use UI scripting and Keyboard Maestro, which is outstanding although there are always little changes in the webpage that keep things from working smoothly. I am trying to get a fast, reliable option that puts the data into the fields I need all the time. Can anyone help me get moving in the right direction?

Model: Macbook Pro
AppleScript: 10.7.x
Browser: Safari 535.19
Operating System: Mac OS X (10.7)