Assuming they could manipulate reality using their mind, they would also be able to manipulate it by speaking about “what’s on their mind”
Technically yes. Considering they're just saying what is being said in their mind.
Yes I see no reason why they cannot. They can either do it directly or in a roundabout way
Intent is what matters they could use their voice to like focus their thoughts on what they what to happen
But it's not necessary to speak
Yeah
What do you think?