i've another test, dumbed down the rendering, turn off high dpi, and it went 55-60 fps. i think for now i will publish this as a desktop app. and restart the mobile version from scratch, use less layer, simpified the graphics (no transparency) . in flash is as easy as using vector graphics and it will scale perfectly in any resolution with lesser fps toll.
its not about the sounds playing at once, no problem togling all the sound, it still getting 30ish fps.
on high dpi mode and fullscreen, it went 30ish on idle and 10 fps when played. so this is definitely a scaling issue.
another question, can i place all the menu / options in another layout, but the music still playing in layout 1?