As of right now, Paul is the team's top LH PH. I'd even list him as the 4th OF instead of the 5th, mainly because he can spell Ludwick vs. tough RHPs. He hit all the way up the ladder in the minors too.
As for his defense, seems competent enough in LF and I wouldn't freak out if they played him in CF on occasion. I would recommend putting absolutely no stock in his defensive metrics in that his sample size is exceedingly small and he's never played a single position in the majors with any regularity.
He should be a lock for the 25-man and he'll be around as long as he keeps producing. In other words, it's his job to lose.
I agree, I'd like Paul on the team, but I don't see him starting many games in the OF. I didn't think his defense was too good, just based on my own observation.
Heisey will get the most starts of the bench outfielders. I think he'll back up all three positions, and play late inning CF defense.
But that doesn't diminish Paul's role. I see him as providing the LH hitting depth the team has needed for years. He'll pinch hit, come in on double switches sometimes, and start here and there.