1. I think for the majority of cases sizeof(char) isn't needed however I couldn't find any guarantees that it will always be 1 byte. I'd leave it in even though I would guess that with 99% likelihood it will never matter.
1. Good question on the multi-byte stuff, I did a bit of digging at some configuration values and it actually looks like stuff in the files is all interpreted as chars and not wchars (for example our worker list file) so I think you're at least consistent with the existing stuff here.