I agree 100% with bolded. His time around kenobi was key to unlocking those abilities as obi wan had already showed him what was possible with the force. By the way I'm not the only one that thinks obi wan used the force to move object when distracting those troopers on the death star.
"Elements of The Force in A New Hope
Additionally, Obi Wan distracts some troopers when disabling the Death Stars tractor beams. It does not seem to be a case of another mind trick, rather that he makes an object fall, causing a noise which distracts them. I can't find a clip of this at the moment, but I did find this spoof which still shows pretty much what happens!" same clip I posted.
Kenobi also does something to make a noise when distracting the guards by the tractor beam controls. The obvious assumption is that he made something fall or move to generate the noise. –
https://scifi.stackexchange.com/questions/93628/elements-of-the-force-in-a-new-hope
At least as of the first movie, Obi-Wan can't just "broadcast" his Mind Trick: it seems that he has to interact directly with anyone he wants to affect. Later movies have shown that the hand-waving gesture may not be necessary: Rey uses it when shackled to a chair, unable to move her arms. But we never see anybody affect someone without at least speaking to them. Actually speaking is probably not as important as communicating your suggestion in some way, but we never see anyone use the trick without speaking, so we can't confirm that.
Although Obi-Wan could probably affect many people on board, the need for communication and the station's own architecture make it unlikely he could affect them all. The guy at the other end of the hallway, safely out of earshot, would likely not be affected. Same for the people watching the security cameras, if they had the sound turned off.
Does anyone have the official novel and if so how does it describe what he does there? When he scares off the Tuskan's he isn't using a mind trick to implant that sound in their mind, he was actually vocalizing/mimicking a krayt dragon call which they were scared of (according to the novel). I couldn't find any excepts from the novel describing that death star scene though.