[snacksthecat]

My cousins have given up and changed their name from O'Keefe to OKeefe to avoid the single quote headache that seems to plague a lot of systems.

[Symbiote]

An alternative which is truer to the original would be to use Ó. It means 'grandson of'. But perhaps the other part should also be "deanglicized", giving either Ó Caoimh or Ó Cuív.

https://en.wikipedia.org/wiki/O'Keeffe

[lostlogin]

By deed poll or just by filling in the form differently? The idea of having to fill in the "have you ever been known by another name" section on forms just looks like a world of pain.