Thanks to his bowling performance, there is no doubt that he is an integral part of limited over versions of cricket.
Nawabzada Shahid Khan Afridi's place as a batsman is certainly something to reconsider seriously. Whether he is fit for Lower order, Middle order or Opening batsman, is something they need to brainstorm again.
Of course there must not be any dispute in keeping him out of Middle order batsmen list because he is not an inning builder player. He is just a destructor or constructor.
Now, is he fit as a Lower order batsman? is a question this post has been created for. This point needs to be understood as soon as possible. There is a huge imputed psychological impact of his position (as 7th batsman) on all upper level batsmen. Afridi is, never a doubt, the biggest hitter in the history of cricket and his being this has a lasting impact on upper level batsmen. When any of those batsmen thinks that Afridi is still there to come for batting, his own commitment is compromised, he comes in an unintentional relaxed mood and in doing so the chances of some mistake are increased and they do. Thus as far as Afridi is somewhere there in the lower order, there is no chance of a consistent performance in upper/middle order batsmen.
Last option remains as an Opening batsman. I shall only add that if he plays as an opening batsman, the danger to Pakistani batting line up will be reduced. At least he will perform better than what he has already done as opening batsman.