I know this was asked a few days ago, but I think I can answer the question about whether being in musicals gives you an advantage.
Some musicals are dance musicals and require a decent level of ability (ie 42 Street, Chicago) but most don’t. Its also often the case that there’s a chorus made up of professional dancers, but the main parts don’t need to do much more than learn a few basic steps. I worked on a show Craig RH directed, it wasn’t a dance musical and i doubt any of the actors in it would have gained a shred of advantage from it if they ever did strictly.