Random Moving Scaleable Vectors

Ive been attempting a particular effect one can see on a variety of sites; the best of which can be seen here: http://www.reschio.com/enter.html

I, on the other hand, have attempted to create a flowing “sea” of a similar dynamic; however, I have been using the time line and stage for orchestration using wave shaped vectors of different sizes and opacities. I find it is too complex and a nuisance to maintain - and well it flat out just doesn’t work as nicely. So, I have turned to AS.

But, given my infantile knowledge of AS I draw a blank on how to call these vectors randomly each with its own randomly assigned speed (x_coord), and each with its own exit speeds (_alpha goes to 0). I havent the slightest clue where to go with this and would appreciate some idea as to how to assemble a vector that can populate the stage randomly as in the above example. Thanks.

Ive spent a little time constructing the following plan of design for what I see needs to be addressed in code. I should be a little more specific in mentioning that my trouble with designing this really comes from figuring out how to assign randomness to each of the following via AS:

(Stage Size: 1280 x 800)

Object size:
• Width: Scaleable within parameter constraint/cannont exceed 1/2 of stage (640px)
• Height: Fixed at 800

Object Movement On Axis:
• X-axis: Movement of object is arbitrary and random in + or - direction
• Y-axis: No movement/static

Object Placement:
Object placement at starting points along x-axis is random given stage dimension constraints

Object Speed:
Speed of object along x-axis is random/variable, but within a specific range of speeds +/- 10 to 15

Initial Object Opacity:
Introductory Object Opacity is fixed at maximum value: 100% _alpha

Object Opacity Dissipation:
Across life of Object Movement On Axis Alpha fades to 0%

Certainly there must be an efficient way of handling all this that I am overlooking.