Getting to know your characters is seriously the most important part. You can have tropey plot elements, but the interesting part is seeing how your characters react to the situation and to each other within the situation. Define your characters and your characters will tell you where the plot needs to go.
I’m sure he means it when he says he wants to end it in five years. Whether he actually does is another matter. I mean, wasn’t Oda’s original goal for One Piece to last just 5 years in total? And now we’re into its 3rd decade. If it went another 10 years or even 15, it wouldn’t shock me one bit.
The Shonen Jump app is amazing, as last I checked there were at least 950 chapters of One Piece available to read. He sure as heck is not trying to beat Kochi Kame’s record.
This is what got me into shoegaze. I still need to check out the new album they put out