Valley Beyond and the Forge- Questions about why..

1. Why was the host Valley Beyond Virtual Reality (VR) triggered at that particular moment in the Forge? Could it not have happened earlier? Which leads me to the next question..

2. Why was the entry into the VR a “door” at the end of a cliff? It is just a VR. A trigger could have been sent to the hosts mind anywhere through whatever network the VR was using, and they consented entering the door (in any form anywhere), and their digital minds gets uploaded into the VR as soon as they said yes. Why that cliff?

3. And how did Dolores figure out to scramble the beam machine to another location, which could never have been found. Why hadn't Ford (or Bernard) thought about THAT in the first place? Surely, he (or Bernard) did not design the Valley Beyond to just hang around in Delos space?

Although I was really impressed, when I first saw it, it retrospect, I feel a lot of it was just contrived for drama (the dramatic exodus and falling down the cliff) and trying to make a point that choice is important (Dolores *suddenly* changing her mind after she gets into Hale's body that she is not going to destroy the Valley Beyond, when she has been stuck on that goal the entire season). It was just not weaved together properly in the last 1.5 hours.