You can very easily install whatever version of Node.js you want using this bash script: https://gist.github.com/a0d40f1ff1679ed582a5. Also, MongoDB isn't even installed by default on the Node.js instance.
As for your bash script... I stopped compiling binaries ages ago, why would I want to start again when I can just use Ubuntu and the official NodeJS PPA?
As for your bash script... I stopped compiling binaries ages ago, why would I want to start again when I can just use Ubuntu and the official NodeJS PPA?