As a fellow Romanian, I don’t see how Vietnamese is that different from Romanian in its writing system. They both overlay information onto the Latin alphabet, Vietnamese merely does a lot more of it.
It's not, that's my point. And yet, I don't often use Romanian diacrtics when writing English, and I certainly don't feel an international audience loses something if we talk about driving down the Transfagarasan instead of the Transfăgărășan.
I feel differently, I always write the diacritics. There are fewer ambiguities than in Vietnamese, but enough to matter. And everything has Unicode support now.
Handwriting definitely doesn't have Unicode support. And neither does people's reading. It may even be easier to guess what someone is mispronouncing if you see exactly what they read (i.e. the letters without diacritics) than if you see the diacritics and forget they mean nothing to the other person.
