So what is a "person" exactly? How is it different than a manifestation in modalism? Unsurprisingly, it's the question that never gets answered by Trinitarians. It's not uncommon to see the term "person" used to describe the doctrine, but its rarer than rare to see it ever actually defined. Usually we get those "Water, ice, and steam" descriptions that are basically modalism. I think Trinitarians would be best just admitting that their doctrine and interpretations of verses are essentially Sabellianism with some Nicean wordplay tacked on, they should just join the Oneness Pentacostals, I think they have the best understanding of "Trinitarian" dogma.
As for the word "Lord", we see that the Greeks had the same habit of using the word "Lord" as we see it in English in replacement for the name, it can be difficult to determine when it applies to lower case "lord" like how David was called "Lord", and when it applies to the actual Holy name, but reading in detail, it doesn't seem Jesus ever shared the same usage of "LORD", and was only called "lord".
I challenge anyone to actually present a link that goes into detail of what "person" means without just using the term as for granted.
Also, as for Jesus being "fully divine", what does the word "Divine" actually mean? Is only The most high god (and He is called "Most high god" for a reason, because he's the highest of the gods) considered "Divine"? Are the "Angels" (called "Elohim" in the OT) not Divine? If they are, then thus it's not a problem for Jesus to be "Divine" as in "a god", a separate being, distinct from the Father, not a different "person" (whatever that actually means), but a distinct "being" altogether with a separate mind and soul altogether, but still a "divine being".
If anything the doctrine of the Trinity is based on some hollow wordsmithing, revisionist ideas of Old Israelite Theology, and twisted grammar.