The explanation given by Strange is reasonable enough. He saw all the possible outcomes and chose the one he did for a reason.
Attempting to use the full power of time stone against Thanos would not have guaranteed a victory. We've seen villains thwart the time stone before; Kaecilius was immune and he wasn't holding 4 infinity stones at the time. On top of that, Thanos shatters Strange's mirror dimension without even flinching. Strange's magic isn't unbeatable, like some people seem to think. Neither is the time stone. We've been shown this, more than once.
Destroying the time stone doesn't guarantee a victory either. Thanos has already leveled several civilizations. He balanced Gamora's planet without any infinity stones in his possession. He almost does the same to Earth in Avengers 1, without directly wielding the stones himself. He wipes out most of Asgardian survivors using the power stone. By the time Thanos arrives on Titan, he's probably already strong enough to conquer Earth. At this point, the only reason for him to complete the gauntlet is to take care of the rest of the universe in one fell swoop. Destroying the time stone doesn't save Earth.
But in the situation, he wouldn't have had to use the time stone on Thanos specifically. Only on Quill. Thanos is very powerful, but it would have been child's play for Strange to remove the gauntlet from the equation once they got it off him.
And that's the thing. The writers know this. They know that the audience knows this. That's why they put in that scene where Strange says "I saw millions of possibilities and we only win one." Once they say that, they can justify every single action from then on as "well, this must be what happens in that one possibility." They might as well have flashed a writer's note on the screen that read "No matter how odd it may seem, we promise that this is the only way it could happen because reasons."
Let's suppose they pull off the gauntlet and Strange teleports it away. Can Thanos still complete the gauntlet in that scenario? Maybe not. Can Thanos still bring Earth to heel? Very possibly, yes. Thanos has already devastated entire planets without any stones in his possession. He wiped out Gamora's planet. And he had to beat all of Nova Corps to re-acquire his first stone, immediately prior to the events of Infinity War. Nova Corps may not have the x-factor of the Avengers on its side but it's a considerably more advance and well-defended civilization than humanity is.
Removing the gauntlet doesn't remove the threat against Earth.
Uhm, you forget, since the infinity stones are in the Heroe's possession, the good guys can just use them to thier advantage. They were already using two infinity stones.
And like you said Nova Corps don't have Avengers and as far as I know, they have 0 superheroes. Even Spider man can withstand Thanos blows with his face, he alone quantifies for more than the entire population of Nova Corp or Xandor together. So nevermind earth with Thor/Stormbreaker (which can withstand the power of 6 infinity stones btw), Wakanda and their Vibranium supply, Scarlet witch, Vision, Hulk (assuming he gets out), Strange and the infinity stones? Then there's also this person called Mrs Marvel.
They would fuck Thanos up. Also lets not forget Thanos had 4 henchmen by the time he invaded Xandor, Maw was dead and the army on Earth was getting routed by the time Thanos arrived.