The answer depends on the laws in your jurisdiction. Most intestacy laws treat a minor child differently recognizing the need for a parent to provide for minor children. In most jurisdictions in the US a parent cannot disinherit a minor child. An adult child can be disinherited in many jurisdictions as long as the will meets the requirements of state laws. The law in the UK is different.
No. Adoption removes the rights to the biological parents' estate.
In most jurisdictions a legally adopted sibling is a legal heir. You would need to check the laws of your state. You can find state-by-state intestacy laws linked in the related question below.
There is no executor if there is no Will. The estate must be probated and the court must appoint an estate representative. That representative will have the power to request a license to sell the property. The representative should ask the attorney who is handling the estate how to handle the sibling who made their home with the deceased parent. The sibling has property rights and rights as a tenant.
yes he/she is allowed
That depends on the State the will is probated in. For instance, in New Jersey, an adult child has no rights to a parents estate if he was not mentioned in the will. The parent has the right to give his possessions to a charity if he wishes to do so.
the sibling that hasn't been adopted normally would have the rite to go and see their adopted sibling but it is up to the adoptive parents, social workers advise the adopted parents to allow the siblings to stay in contact but at the end of the day it is up the the adoptive parents to deside,
Generally, the status of a person as a "sibling" is not relevant. What is relevant is whether that sibling is or is not a beneficiary under the will. An executor has an obligation to give information to the beneficiaries of the estate as named in the will, not to all the decedent's relatives. If a sibling (whether it is a sibling of the decedent or of the executor) has no interest in the estate, he/she has no rights to information about the estate. In some jurisdictions, an executor might be required to simply give that sibling notice of the probate of the will, even if the will gives that sibling nothing, but only if that sibling would inherit some part of the estate in absence of the will. As with all legal questions, the specific answer may differ from state to state depending on that state's laws. So you must check those laws to get the precise answer.
There is no requirement for a sibling to be in a will.
The estate pays for the funeral. The 'significant other' may not have any rights to the property or any portion of the estate. The estate gets to pay the debts first, then it can be distributed.
Marriage does not affect the rights to inherit in the US.
Yes unless there's a will or court order saying otherwise. The remaining family is usually the ones packing up the belongings.
In general, living arrangements typically do not affect the rights of siblings when a parent dies. The distribution of assets and inheritance is usually determined by the parent's will or state laws, regardless of where the siblings live. Each sibling is entitled to their fair share of the estate according to these established guidelines. Consulting with a probate lawyer can provide specific advice based on the individual circumstances.