There is no requirement that you probate a Will no matter how much the estate is worth. Wills need to be probated only if property is not transferred by some other means.
You may be confusing probate with the filing of a federal estate tax return. Regardless of how the property is transferred at death, if an estate is valued at $5,430,000 or more in 2015, then a federal estate tax return must be filed. And yes, you must include proceeds of life insurance owned by the decedent in computing the $5,430,000.
The probate process is primarily a method of changing title from the deceased to the person or persons who inherit the property. Some assets require probate, such as real estate and bank accounts held only in the name of the deceased, while others do not, such as life insurance policies or retirement plans payable directly to named beneficiaries.