To say the Vikings are lacking playmakers is an understatement. Why not go out and grab one of the best receivers in the draft? Honestly, if I were the GM, I'd try everything to trade out of the pick to pick up more talent in the top 2-3 rounds. But, being the fan of the Bengals that I am, I totally understand how hard it is to trade out of the top couple picks of a draft.
So, if your stuck with it, why not try to make the most of it with an 'explosive' player? You can always find solid OL later in the draft. You can't always find a WR playmaker.
Or, some more food for though. Take Richardson? Heck, why not? Throw a wrench in this draft! besides, taking a top pick now a days, doesn't cost a team like it used to if their top pick didn't pan out. And, is everyone really sure AP is coming back 100%? After you tear an ACL, its really hard to make back to what you were before. Take Richardson for insurance purposes and then work on your OL and secondary later. If you take Richardson, i guarantee teams are going to be on the phone begging for a trade.