I like your makeup and think that the simple addition of a muzzle looks just fine. The reddish blush on each cheek frames your nose nicely. I don't think you need to add any red to extend the nose, but there are noses which cover more fully than the nose tips which you may want to try on sometime just to see if you like them any better or not.
there are noses which cover more fully than the nose tips
I can't stand covering my nostrils! I did go from the smallest nose tip (proknows T-1) to this one (proknows LT-1).
You could probably cut out the underside of a nose if you don't want to cover the nostrils. I'd doubt many (if any) would even notice. But if you're happy with what you've got, then stick with it! It looks fine.