As far as I know, there’s no way to have line breaks in any dialogue. When I was working on Poetry Adventure!, a game where a lot of poetry was involved, I just used slashes to show where a line break would usually be, but it still isn’t ideal. This is a bit tedious, but maybe you could try to put enough spaces to make the dialogue appear to have a line break? As for the symbols, there’s no way to copy and paste symbols into the game. You could try to get around this by doing something along the lines of -> and <- for right and left, but again, it isn’t very ideal.