Is there a way to get the launchable activity for a package from using adb? For an unroot phone (i.e. without having the pull the apk from /data/
You don't need root to pull the apk files from /data/app. Sure, you might not have permissions to list the contents of that directory, but you can find the file locations of APKs with:
adb shell pm list packages -f
Then you can use adb pull:
adb pull
and then aapt to get the information you want:
aapt dump badging