Okay, I have finally finished reading Part 1. Now, sigh, I look at the questions in light of what I've read ... and I don't have answers.
I felt less alone in my confusion and more confident in rereading and posting up some sort of answer.
One thing I thought about as coming to the end of reading this part was when did Lucia know that Seingalt was Giacomo? When she first saw him walking from her boat? At the theater? That night at the house before the storm? Or didn't she know until he told the story of the girl he first loved to her?
Okay, going to go reread bits of part one now.