Where you can find other functions - MRandyPE/Addon-Functions GitHub Wiki
To get all mangled function names, you can simple run 'objdump -d libminecraftpe.so | grep "_ZN"' in folder with libminecraftpe.so.
To automatically demangling, you can use http://creepworks.herokuapp.com/cpp/demangle.html, or other online tools.
Another way to find all of the functions is to use IDA which let's you decompile the libminecraftpe.so file with ease.