Doubtful it's the wrong mast, as NP sail + NP mast should be ok? Are they roughly the same vintage? Also ask your retailer, they should be able to help you get it rigged right especially if they sold it to you.
I basically ignore the batten/mast relationship, and just look at how loose the leech is. I think with NP sails having the top panel loose about 50% of the way in from the leech to the mast would be a good place to start. I think it's okay if your battens sit next to the boom, especially the lower ones, as once the wind fills the sail, they will pull away from the mast and make that nice aerofoil shape that we all love. Take the time and actually look at your sail when you are sailing, who cares what it looks like when it's rigged on the grass, it's gotta look right when you are sailing! And don't forget batten tension, as this is often overlooked and can easily make good sails feel rubbish!
Also, with downhaul settings, you probably only got a 10mm sweet spot range to play with, outside of that your sail will probably handle like rubbish, so once you find that sweet spot, remember it, write it down, do what you need to do! I generally find that once the sail is in that downhaul sweet spot, all I do is adjust the outhaul to keep the sail just off the boom as it gets windier. If it's so windy that I feel the need to yank a whole heap of downhaul on, I just go grab a smaller sail instead!
Sometimes you can get sails to work with the wrong mast, i.e. I used my new 5.6m S-1 last weekend with a powerex mast (note to all the punters, NOT A GREAT COMBO), however a bit of tuning, I managed to get it pretty well sorted for the light winds at the time, but top end range was pretty compromised. Got the proper mast now

, it makes things work better, but you still need to get it tuned right!