Looking for suggestions/help with Adventure Engine

With the release of Construct2 r117 and it's grand, new pathfinding algorithm, I thought it was about time to commence work on a point and click adventure engine.

So far, so good. A few hours later, I've already written up a few white papers and am in the process of drawing up the UI (I've decided to go with a non-native look for this one. In the end, it should look quite different from standard wxwidget/QT apps).

Here's where I could need some help with, though:

1. The "menu bar" will consist of several list boxes. I'd like to mark the first entry (the one that's there whenever the program is launched) with bold. Is there any way I can do that in Construct2 (using CSS)?

2. Any suggestion on how to accuratly implement animation changes? Say, when the character walks to the back of the screen and thus isn't facing the "camera" anymore? The way it's currently implemented (compare sprite position to mouse.Y and switch animations accordingly) isn't exactly usable.

3. My goal is to have a toolkit which, in the end, won't rely on Construct2 for anything but re-packing the interpreter module. For this to fully work, I'll obviously need a scene editor that keeps track of the pathing itself (some sort of hidden polygons that seperate the walkable areas from the ones that are restricted). Any suggestion how I could generate some sort of variable polygon structure on the fly, which will then behave like some sort of solid or custom obstacle for the pathfinding behaviour?

4. Any opinions on using Javascript (via CallJS) as internal scripting language? My major fear is that a) it's too hackish b) it might lack certain features/syntax that are a standard with scripting languages like LUA or AGS Script.

Here's the .capx, for anyone who's interested:

docs.google.com/file/d/0B4HbmIw0kk7FMHh5SC03NlZJYVU/edit

Ok. Finally figured out some basic movement.

It's still a wee bit flawed, so I'm thankful for any pointers on the math (fixing it mathematically would probably be the elegant solution)or whether I should, perhaps, add another condition dealing with area left and right of the character.

docs.google.com/file/d/0B4HbmIw0kk7FWWktWnowUVJCbkU/edit

EDIT: I could, of course, simply add a hidden sprite and calculate the animation based on angle. I'm not sure, however, if this would be a more proper approach or not. It would certainly add more overhead, which I'd prefer to avoid.

The game I want to develop with it will use pre-rendered 3D characters, so I'll definitely need more directions than those four already in place.