Wow which beautiful stage.Nice work.
BTW you can use animated Stage elements in ShugenDo.
First you have to put you animation info to an air file.
Second add that air file to your stage xml file
like this
<Files>
<!-- Generell files -->
<Spr> arena96.sff </Spr>
<Anim> arena96.air </Anim>
<Snd> </Snd>
<Music> </Music>
An now here an example of the animated bg element
<Element type = "BG">
<BgType type = "anim" />
<BgId value = "-1"/>
<Anim number = "0"/>
<Coord x = "-60" y = "240"/>
<Delta x = "0.4" y = "0"/>
<!-- 0 for background (behind characters), 1 for foreground (in front) -->
<LayerNo value = "0"/>
<Tile x = "0" y= "0"/>
<TileSpacing x = "0" y= "0"/>
<Trans src = "255" dst = "0"/>
<Attributes masked ="0" xScale = "1.0" yScale = "1.0" rotate = "0"/>
</Element>