About the android version issues, the same problem happend to corrupted kingdom and champion of realms. But they both found a way to make the apk work so you should do your research if you can. Thx for your effort anyway
You can reduce the size by compressing images as android doest need hight quality image due to small screen or go the way pale carantions and others went by making 2 files apk and a data file that can be pasted
