1)+2) In canon, apparition and portkey creation are both pretty advanced magic. (Apparition is typically taught at Hogwarts to 6th year students, while portkey creation is not part of the curriculum, as far as I know.) Unless you have a good indication that Harry knows either of those spells, I consider this highly unlikely.

3) Even if Harry manages to force such a magical interaction near-instantly (which I will consider unlikely until I see a sufficiently detailed description), since this will not help against the Death Eaters. And before Harry is able to perform a second move, the Death Eaters will have killed him in their first move.

4)+5) Transfiguration is an interesting possibility, but both plans seems unsatisfactory to me; not quite sure, why, though. I’ll have to think about that again …

6) Again, any plan that does not incapacitate the Death Eaters very quickly, seems unlikely to work.