Core Shot - Laminate - Swirl

I just finished machining my first injection mold the other day, and have
various supplies ordered to experiment with.

Based on reading various threads I think I already made one mistake with my
prototype. I don't think I have enough reservoir built in to account for
shrinkage during cooling. Not that big of a deal to fix though I think. The
first one was a prototype to figure out how to machine the mold. I figured I
would run into some issues with this first one.

Upon reading the various manufacturers websites it seems you are supposed to
get a decent laminate bait by just taking to two injectors with nozzles to
match or a mating manifold and injecting the liquid plastic side by side
into the mold.
1. Does that give a decent uniform Laminate?
2. How would you make a laminate that is other than 50/50? Just use two
different diameter injectors?
3. Why doesn't it swirl when you do that? Particularly in a detailed mold?

Core Shot. Another site I read says you can get a core shot affect by just
filling the mold with your main color and then shooting in a different
color. How does that work? If that doesn't work, how about using a basting
syringe, inserting it into the mold and then withrdrawing it as you inject
plastic in the core of the bait?

If the laminate method listed above does not swirl, how do you get swirl
pattern baits?