The 'help' in the flash environment is very, very, good. Use it whenever you're stuck.

I find trace statements are a much faster way of finding-out what's wrong than the debugger, but maybe that's just my Java and C++ experience giving me an upper hand there.

Coding something specifically, or doing a specific page or frame for a function, is OK if what you're coding is an oddity. For everything else, I'd try and make the pages as general as possible. When you're selecting chassis type, for example, I'd write code that built a set of buttons from an array of chassis_id/name pairs rather than doing a page with X buttons on it. It's well worth learning how to use the square brackets notation to build programs that can cope with an unforeseen number of buttons and similar. IE: use mc.['button'+i] rather than mc.button1, mc.button2, mc.button3, etc. It may be slower in run-time, but it'll save days of time re-doing similar pages over and over again.

In-general we'd make the text for a button as a text box in-front of the button rather than part of it. That solves the problems you're having with different text on the roll-over. A simple colour change for the background (darken or lighten, maybe a different gradient?) is a good substitute for the hop-down-right if the button's not visibly angled. This also means you don't need specific buttons for each item, a general button with a dynamic text box infront can be inserted from the library using attachMovie. This code, if inserted into a fairly standard for loop, will create a bunch of buttons as long as you have an appropriate button movieclip in the library:

this.attachMovie('buttonStd', 'button'+i, this.getNextHighestDepth(), {_x:100, _y:60*i});
this['button'+i].label.text = i;
this['button'+i].button.onRelease = function () {trace(this.label.text)}

Note, the button movieclip would need to be exported for actionscipt (as 'buttonStd') and exported in the first frame, both of these options can be found in the linkage options in the library. It would need a button (a movieclip is generally preferable since flash 7) with instance name 'button' and a dynamic text box with instance name 'label'.

XML is a good format for external files that aren't binary. This is obviously only IMHO, but I find it's easily understood and modified by all (even TV Producers!). Generally: People who've used HTML can cut it, and that's a lot of people.