SWGE cast members have always been allowed to say "May the force be with you"; they just save it for appropriate moments. It wouldn't be as special if you heard it all the time.
Not sure when exactly they swapped them out. At first glance they look like the same wooden tables, but the main difference is the bench seats instead of regular chairs.
It has changed in the park as well, unfortunately. Actual food name in big letters with the themed name under it in smaller letters and then the description of the meal. Used to be the other way around.
R2-D2 would meet occasionly during SW Weekends. All the other R2 units have only been out during Galactic Nights events and they were provided by a Droid Building fan community, kind of like how the 501st used to participate in SW Weekends.