Hello Lester. Yes, that's what it means. "Some years later" is the correct structure, or one could say "After some years," but the phrase "After some years later" is not correct (even though that is the meaning). By the way, the preposition "in" should be "to," as in "moved to Florida." Thank you for asking!

It means more than one year later. I probably wouldn't say "some years later" unless it was three or more.

"Some years later" means "after a few years." You don't need to say "after" again; "later" already implies it. So, it means "after a few years" or "a few years after."