Try opening a bank account like that. I can guarantee you it's not going to work; they will want to see a passport and proof of address with exactly the same name. I've been rejected by banks just because the utility bill shortened my second middle name to just "P".
This seems true for pretty anything of substance: government, tax, banks, insurance, health care, things like that. I'm not a lawyer and don't know how it works according to the letter of the law, but de-facto, you will have a "legal name".