Visitation interference is a serious matter. When parents are granted joint physical custody of a child, they must agree to abide by and respect the visitation time of the other parent. If one chooses not to do so, there are legal remedies available.
Though a person may spend a lot of time in preparing a well thought out Last Will and Testament, things do not always go as planned. If that person does not update their will as ownership of assets change over the years, then those which are deemed to be the inheritance of another person may not always be available. In addition, if a person's financial situation changes, then upon their passing the estate may not hold enough funds to distribute money to a beneficiary. There are rules in place for these situations which determine whether a beneficiary is still entitled to anything.