1. I think this would be a good fit in the Library, with some more work on it.
2. I only see one article here, where is the second one? I think this would be really interesting as a short series!
3. I don't think this is ready quite yet, but pretty close. I think you did a really good job with getting me hooked at the start, I thought it was kind of funny how Finnagan was holding on to the side of the boat—however, there is more that can be done with laying out the setting. It could be cool if you were to add a scene where Finnagan is sneaking off, because this would answer a lot of questions (What are some little things about his character? What are some little tidbits of his culture? How did he even see the ship? How is he the only one that noticed, is it early in the morning? Is it really that easy to get past the island's defenses from the inside if you are a Pelagos, or does it trap people, too?). Of course, this might ruin the flow you have at the start, but adding one more small scene to the beginning or end of this would make it more suitable for posting because of the information you can include without making this an info-dump.
4. Hmm, as far as characters go…I think the Dr. could be improved. Why would he say there's a kid in the first place? He seems like the reckless "Investigation first, reports later" kind-of-character in these types of fantasy-meets-modern-science stories. Finnagan is believable for the most part (the main improvement here would be with adding another scene to really solidify him as a character that readers can find likable and as someone that we want to read more about).
5. Tone is fitting, I'd say, since it's the perspective of Finnigan. There should be more fear or suspicion from him, or some other emotion (like confidence or arrogance or naiveness), when he's interacting with the Dr. I don't really know too much about Finnagan though, so that's your choice, in the end.
Thank you for your specific questions. Let me know if any of this helps, and post again here when you've made some revisions/if you want someone else to help you out with any questions you have!