Glad to have your interest! That is an absolutely understandable concern, but there are a couple ways to deal with it.

One is to chase one of the GM threads, like the Witch of Webs or Grime King. That way, you can write your own arcs as you please, but you can also get involved in some of the larger stuff in the Blue Sea through having me to play off of (albeit through NPCs rather than PCs), which could also result in paths crossing with other characters later down the line.

You can also join a crew! We currently have the Inferno Pirates under my character Rico, and Doc Tachyon's in progress sheet has the Vagabond Pirates under Hakka Jitte. We also have at least two Marines and a handful of other characters in the works, judging by discord conversations. I'd wait until the relevant character is accepted before going full in, but in general, you are absolutely welcome to PM another player regarding character connections (though you might need to join the discord/ask me if you want to know what the other players are working on)! I'm actually working on a character specifically for the Vagabond Pirates, and am even keeping ideas for the joining arc down to discuss with Tachyon in the future. If you reach out to me, I will gladly explain more about Rico as needed so that we can plan how our characters will start the Inferno Pirates proper, if that's how it goes. Of course, the obvious downside to latching your character to another player is, what if they drop the game? If I drop then the RP is probably over, but in the event of the next worst thing, as I talked about in the post, I'll do my best to work with the affected players to figure out how to continue your character's story in the absence of the missing player, but...

We do allow multiple characters! If you're writing on your own for a while, and not liking how things are going without other players to bounce off of, then it might be apt to temporarily retire the character until later in the RP when there are more options, and play a new one in the meantime. Obviously it's not ideal, but as long as the game's still going, there's potential for new ideas to come about, whether its something you can do with that previous character now that the game has advanced, or maybe you'll have come up with a character idea you're more interested in!

Hopefully I've helped alleviate some of your concern, but feel free to ask me if anything else comes to mind.