You can't over stabilize.
You can however spin the light and fragile varmint bullets fast enough to take them apart in the air.
True true!
When you spin the bullet too fast, the jacket tends to heat up, expand, and then get pulled outward by the centripetal force, tearing the bullet apart.
To some extent, you can speed a bullet up and use a slower twist rate and still get it up to enough RPM's to stabilize it, so you can have some versatility in bullet weight with nearly any twist rate just by varying the velocity of the projectile.
The formula for calculating the RPM of a bullet is simple, MV X (12/twist rate in inches) x60 =RPM, where MV is the Muzzle Velocity of the projectile.
Most bullet manufacturers recommend a twist rate for each of their offerings in the way of projectiles, but you may have to dig a bit for that info from them.
You can also calculate the twist rate required to stabilize using the old Greenhill formula, and get pretty close, remember to use 150 as the constant for projectiles moving less than 2,800 FPS, and 180 for ones moving more than 2,800 FPS.
The original Greenhill formula was:
Twist = C * D * D / L where
D = Diameter of the bullet in inches
L = Length of the bullet in inches
C = A constant (defined to be 150 in the original equation, but as I said, use 180 for more modern, higher speed projectiles).
There is a more modern version of Greenhills Formula that takes into account the material the projectile is made from, where Greenhills just assumes lead, or lead with a gilding metal jacket.
That formula is:
Twist = C * D * D / L * Square Root of (SG / 10.9) where
SG is the Specific gravity of the bullet material.
For a lead core bullet, SG = 10.9, which would mean the right part of the equation is equal to 1.
For other materials, the value of SG varies, for example, for Copper it is 8.5, Brass is 8.9, Steel is 7.8.
So with the above you can look up the projectiles you want to use, and do some rough calculations using the velocities you want to launch each of them at, and get an idea of what twist rate will come closest to a "do it all" rate for your application.