Well, if the raiders deal moss and get a qb in return, they will definitely pick Johnson. I don´t know if the vikes or fins will trade up to nr. 1! they would give up a lot! If the raiders pick a QB, it´s another story.
I think, for the vikes, it´s the best option to trade up to nr. 4 to get Johnson, if he is available, because the need wr and cb! But there is no cb or wr (except Johnson) worthy of picking at nr. 7! so they have to trade up or down! since the fins have more needs, they can get a quality starter at nr.9 anyway!