For the lounge question, aren't we back to the normal discussion which always ends with the O/W rules...
Members of oneworld airline frequent flyer programmes with the equivalent of oneworld Emerald or Sapphire tier status can use lounges offered by oneworld airlines when departing on any flight marketed and operated by any oneworld member airline, regardless of cabin class being flown (exceptions are noted below).
If Vueling are operating the flight, they aren't oneworld, so access should be denied. People have had success in getting into the lounge though, so you may be lucky on the day.