The drawback are increased costs for coordination and merging of the different languages. Collect these remarks in another file and sent them to me seperately. I'll do these changes, if I agree. The file itself includes more remarks about the strings and a history of changes. MakeCD will ignore such strings and use the English default instead.
All windows have to open on such a screen.
A screen on a graphic card with the same size is not sufficient, because the different pixel ratio actually makes a difference. Some strings might not be used in the last public release yet. I'll send you beta versions of MakeCD itself only if it is really necessary. No key should be used twice. It really helps maintaining the file.