Not to mention Rafiki's Planet Watch is located north of the plot behind Asia, so you would have to go all the way to where Rafiki's Planet Watch is, to come back down near Everest? Not buying it.
No...you wont be entering pandora from where the actually building of Rafiki's Planet Watch is...you will be entering between Africa and Asia.
The train is leaving because it would cause a visual disturbance.
The buildings that house the animals in Rafiki's Planet Watch are moving and will become a walk-through attraction where you learn more in-depth about how disney takes care of injured animals.
TDO is looking to double the size of its animal hospital and conversation + affection station but locating it at another place in the park...might be moving to Camp Minnie-Mickey to give something to that location for guests to go to.