One alternative to using scenes is creating a series of movie clips that take the place of scenes. One of the problems with this is aligning the contents of the movie clips (MCs) to each other and to the stage. One way to make this easier is to create a Canvas Guide Layer:

The Timeline Setup
Place each movie clip one after the other on the main timeline with a Stop frame action in each frame. At the end of each movie clip put a button or frame Tell Target action:

                   Begin Tell Target   Target: /
                          Go to Next Frame
                   End Tell Target

If you use a button action don't forget a Stop frame action, because Movie Clips loop by default.

Common elements between movie clips should be placed on the main timeline, but you can put copies of those objects in a guide layer inside the movie clips to better visualize and align. See Alignment below. Anything in a guide layer will not be exported to the .swf file. Also, objects, that are in a guide layer that is in a movie clip, will not be seen when viewed from the main stage.

Streaming
Movie clips have to load completely before any part of the movie clip will play or display.Keep this in mind when designing for the Web. If earlier sections of a movie are large, it might be better not to encapsulate them in a movie clip to improve streaming.

Alignment
To make it easy there is a one-to-one size correspondence between the size of objects on the stage and those inside the movie clips.

1) In each movie clip create a Canvas Guide layer and place a rectangle the height and width of the stage centered in the symbol area. Make the layer a guide layer

2) You can add other guides in this layer if they fall completely inside the Canvas rectangle, otherwise create another layer for these guides.

3) You can not normally use the Movie Clip's position and/or size for alignment on the main stage (See Step 4).

4) To align your movie Clip to the stage (perfectly):
      a) Turn Canvas Guide to normal temporarily (un check Guide).
      b) If there are no objects or guides that are outside of the Canvas Guide rectangle skip to Step e.
      c) In the frame where your Canvas Guide resides, temporarily turn all the layers that have objects outside of the Canvas Guide's rectangle into guide layers.
      d) Temporarily change the behavior of the Movie Clip to single frame. Remember the Instance name of the MC as you will have to reenter it after you are done with the alignment.
      e) On the stage use the inspector to align the movie clip to be at x=0. y=0 and the height and width of stage.

      f) Reverse temporary steps above as needed.

Calculating position differences between the Stage and the MC.
5) If you know the position of a point on stage and want to convert it to the position in the symbol:
Divide the height of the stage by 2 and subtract that from the y. position on the stage to get the y. position in the movie clip.
Divide the width of the stage by 2 and subtract that from the x. position on the stage to get the x. position in the movie clip.

6) If you know the position of a point in movie clip and want to convert it to the position on the main stage:
Divide the height of the stage by 2 and add that to the y. position in the movie clip to get the proper y. position on the stage.
Divide the width of the stage by 2 and add that to the x. position in the movie clip to get the proper x. position on the stage.