Does this mean "I love you too" in the sense of "Oh, you love me? Well, I love you, too" or in the sense of "I love not just Sophia and Ben but also you"?
I would have expected "Jeg elsker dig også" for the first meaning.
Yes, because adverbs come after the verb. I wonder, then, how you would distinguish between the two.
I think its because adverbs always come after the verb in danish :) not 100% sure though
I, too, love you was not accepted, though in some English sentences that would be an acceptable response, as in "John and Jack love you, and I, too, love you," if you want to emphasize the "also" aspect of people loving you.
for can mean "too" as in "excessively" (for stor = too big = excessively big).
But not "too" as in "also", which is the meaning here.