You're describing a wet/dry type of look.  Any idea the length of the pattern?  I noticed you said that you don't want the ball to check up early so i'm assuming that you've seen that.

I had a Cherry Vibe with a 6" pin that I kept at 1000 grit with a high shine on it using Valentino UFO polish.  I was always able to keep my angles "squared up" with it and try to somewhat take the pattern out of play and use all the hook.  This was my step down from a Hammer Psycho so they were hooking when it was Vibe time.

+1 for the Favorite. OOB, the MM is probably too strong, Crossroad a little too strong off the spot, and anything shiny will be too flippy off the spot as well. Maybe the Karma Solid, but it also depends on how they are laid out.

I can't think of a ball smoother and most likely to smooth out the wet dry than the Favorite you have in your arsenal.

+1 on the Favorite.  That ball has been known to be really good with blending out the wet/dry and having a very smooth downlane motion.  I agree the Modern Marvel and Crossroad would probably be too over/under or too strong off the spot in this case.

My Favorite is too strong. It's drilled 5.5" pin to PAP, pin above the fingers and it's too strong for this condition. It reads and reacts exactly how I want it to, it is just too strong. Is there a ball similar to this, but weaker?

Maybe a blue Hook with the same layout,  or the new Wisdom. You could even look at the new cobra se. Strong cover, light bulb weightblock. Cobra is F74, Wisdom is S65,  and the Hooks are S43.

I am curious as to if that 15 mph is at the pins or at release.  15 at the pins could be 16.5+ at release.  If not, then 15 at release means you are only around 13+ at the pins providing there is enough oil in the front. 

If the 15 is at the pins, you could do the Favorite or Karma Solid.  If not, then you may want to consider stepping down to the Breeze.  Breeze will help push down the lane but a matte finish will help to control the backend of the lane.