Ye maybe its a but more lenient than I thought but keep in mind Gojo is leagues beyond these guys
I don't see this as too relevant in the proposed scenario as Klein is invulnerable, speed is equalized and Klein has precog to know where Gojo is trying to teleport. Enzo even had stronger precog on the level of giving him the cheat sheet of all correct decisions to do at all times and it wasn't enough to escape the teleporting Klein.
He gets teleported a few meters next to Gojo.
Now this is pretty relevant. Though if the prep time was to set up Spirit World Coordinates to retreat to, I don't see Gojo managing to find his physical body after teleportation anyways. Mark a bullet train and teleport to it during the fight after it has already traveled a long distance, the coordinates are more particular about symbols (such as village, ship, city) than distance and set positions, after all.
EDIT: Actually, I went back to check the second book about spirit world traversal. He can teleport anywhere within
Shibuya Tokyo even without proper preparation as the concept of a city is considered the same unfragmented domain in the spirit world.
In essence, Trier as a holistic notion held sway. It boasted a corresponding domain in the spirit world, unsullied by fragmentation or dispersal. Minus precise coordinates, Lumian could solely "teleport" within Trier's immediate ambit. Otherwise, he risked straying into the spirit world's treacherous realm, a hazardous endeavor indeed.
once he leaves the Astral Projection to teleport away, he’ll need to redo the ritual which will cost him time
You mean if Gojo found his physical body he will have to redo the ritual to summon his Astral Projection again? I don't see this as very feasible. So long as Gojo can't find and destroy his physical body within the time he takes to do the first ritual, he gets a 5 second timer to initial control.
How is Ninth Law Charm applied, is this shit capable of just changing the Law's of abilities too?
The Ninth Law charm is an ascended version of the Prohibition ability from a sequence 6 Judge, so there are quite a few examples of what can be done with it in the first book alone (379, 473, 628, 699, 880, 1026, 1146). You can specify an action that cannot be done in the surrounding area so long as it's not overly general (such as supernatural abilities cannot be used). Considering general knowledge of Gojo's abilities, Klein can use it to say: "Limitless is prohibited here" and disable Gojo's cursed technique entirely so long as he hasn't managed to stop Klein from activating it or retreat far enough.
For all charms (...) and then throw it at Gojo
Not Fate Siphon, chanting the word and injecting spirituality is enough. Also, Ninth Law is only technically thrown at Gojo, it scatters into light as into the surroundings, presumably designating the affected area.