jtown

Well, not "guaranteed".  They'll wait minutes but not hours.  If your tour transportation breaks down hours from the port and alternate transportation isn't able to get you back in a timely manner, they're not going to wait all night and throw off the next port's itineraries for the entire ship.  But, as long as your tour is pretty much on time and has no extraordinary delays, you'll be fine.  If you're concerned about the "broken down hours from port" scenario, call RC and ask them what the policy is for that situation.  Ask if they cover hotel and airfare/transportation to the next port.
 
As for breakfast and getting to the excursion, get up early and eat early.  I've never been on a ship that didn't have breakfast available early enough for people to finish eating before the ship is docked.  If nothing else, there's always room service.  When it comes to getting to your excursion, in my experience on other lines, people with early excursions get priority disembarkation if they're tendering.  If you're docked, no worries  It's amazing how fast a ship can clear out.  The excursion isn't going to depart without you.  They know how many tickets were sold, when the ship arrived, how long it will take you to get from the ship to the meeting point, etc.  Don't dawdle but don't stress.