yes a agreement needs to be singed for it to be legal.
what are the consequences of not having a signed and valid agency agreement
Yes you definitely can!
You don't. A signed settlement is a legal binding agreement between you and the insurance company.
Yes, a seller can sign the agreement first, but it is not binding until all parties have signed and the signed copies have been delivered.
No
Yes and no. It has to be signed off by a judge, but it's still a contractual agreement.
If the judge was shown a death certificate for another holder, a change of name perhaps, a signed agreement from the involved parties. Sometimes the property disappears. This is what judges do. A signed agreement IS a signed agreement. No one can be thrown off a signed agreement unless another agreement exists (by those parties), a law has been violated that abrogates the agreement, or the conditions specified in the agreement have changed.
If the age of consent into a legal agreement is above 17 then no lease has any legal standing. Therefore it does not exist, legally.
Very well, if it is indeed a legal contract. If it was legally signed and witnessed, notirized, and recorded at the County courthouse - it's legal and binding.
A properly written and executed agreement is called a contract. A contract that has been executed has been signed or possibly notarized.
The answer depends on the nature of the agreement which you haven't included.
The answer to that would normally be covered in the custody agreement that the guardians signed.