Hi Lilian! I just add two letters to "fantastisk": a missing "s" and an "a" the to get the plural form.
I am not really sure that I understand the last little sentence (maybe it should be changed a bit, but I don't know yet). Does it mean "will you be there for me", "will you come instead of me" "will you be on my side" "will you be with me" or anything else? If you want I could put the translation for a vote, but I think it would be even better to change the last sentence in some way first.
The two lines are addressed to different recipients. The first one, as I remarked is addressed to more than one person, however in the second the speaker wonders if "someone will be for her" (assuming that the writer is a woman)
The bridge could have been : "Will you be mine?", but in the original it says "for/to me" and not "mine", so I decided to stick to the original.
Okay, I see. I think "Ska(kommer) du vara min?" is better in Swedish than "ska du vara för mig?". Another possibility is "kommer du att finnas där för mig"? but it has another meaning, more like "will you be there for me" (when I need you...), so it is not the same thing as "will you be mine".
Maybe we could change it into "kommer du att vara min?" and then let people vote about it?