> How would you bock China's access to the sea along it's 14000 km coastline?

With missiles and submarines presumably.

> That woulde be a heck of a blockade, with or without Taiwan.

Of course, due to China's military build up around the sea. Due to their being afraid of said blockade. The one they want Taiwan and other disputed islands to help counter.

Why block the whole thing when all shipping traffic goes through 3 chokepoints and the chinese navy is brown water at best?

Exactly. We have a westerner bragging about blocking a 5000 years old country's access to the sea like it's a normal thing and they're not the intruder. Hilarious.