First, the instructions should indicate which stars n bars go where, but the larger ones go on the wings.
The wrinkling is part of the process of the Micro Sol (or 'Set) working on the decal when in place.
Leave it - don't touch!
I know it looks alarming, but the decal will settle and conform. If, after say, 12 hours, the decal has set but there is the odd wrinkle or small bubble, examine it closely, and see if a touch more solution can be applied under the decal, with a small soft paint brush, or even on top, which will continue the process of setting. Given that the decals have been placed and squeegeed down as normal, they should smooth out, unless there's any air trapped beneath, which will show as a small, possibly tiny, bubble. If this is the case (once set and dry), then prick the area with a pin, and feed some solution into the hole, and leave alone it will eventually settle, but might need further applications until it does.
As for the chequered nose - have you lost it, or was it not included?
I'm fairly sure I have a black/white nose decal in 1/48th scale, probably off a BBD sheet, although it might not fit exactly. But at least it'll only mean touching-in here and there.
If you want it, bung me an address via PM, and I'll send it - after Christmas, or it'll get lost! (It took over 3 weeks for a small packet to get to Bill (Night Fighter Nut), which should have taken 9 days max !)