No higher than 7. Ideally 8 really. Yes he has potential, and could well be good enough to even bat 6. But if we are going to try to become a consistently strong team we need a strong batting line up. And that means we need bowlers who can bat a bit. There's no question, Shadab merits a spot bowling alone, and him being able to bat while taking a bowling slot is fantastic for us.
If we can not find 6 (or even 7 really) batsmen better than Shadab, when Shadab focuses 90% of his efforts and quite rightly on bowling, while some batsmen don't even bowl and focus completely on their batting, then that shows a sorry state for batsmen in Pakistan. I don't believe that there is such little batting talent in Pakistan to warrant that Shadab has to bat at 6.
We need to really prioritise making a strong batting line up, tail included. Too many times we are ready to weaken it for the sake of an extra bowling option which provides greater variety, but not necessarily improves the bowling line up (as the extra bowler indeed will be the fifth/sixth best bowler in the team). You can see the trend in batting line ups these days, teams bat deep and their tail can bat a bit too. It's the most effective strategy, you can't afford to stall with the tail at the end, you need support to aid the set batsmen looking to hit at the end of the innings. They can't do that if they have to shelter the weak batsmen at the other end.
In ODIs, really your no.8 should bat. Your no.9 should be able to hold a bat. 10 and 11, you can cut them a bit of slack, though ideally only your no.11 should be useless with the bat. That and I'd like them to implement the left/right combo and the top of the order (and if possible through the order). We saw it's effectiveness in the CT, and it's very hard to run through a side when you have to constantly adapt your bowling depending on who's at the crease. I don't think it's great to have two lefties opening together, even though I'd have both Fakhar and Imam in the team, neither has done anything to deserve to be dropped.