There are a very few places where you can legally do that. It varies greatly from state to state.
sometimes. Actually, all the time. Just not legally.
At home only is generally alright. The parent should not encourage excess or regular drinking.
If the drinking age is 21 then NO. It does not matter if they are your parents, if they are to buy you a alcoholic drink then they can go to jail for distributing to a minor.
Can't. The 18 year old is an adult and do what they want.
There are no legal barriers to that relationship.
yes well only if your parent aproves of it
The fourteen year old must have a parent's consent. The 18 year old does not need parental consent because they are not a minor.
you might need a parent consent
yes
Yes, they have the right to tell them to leave. Once the child is an adult, age 18, the parents are no longer legally responsible for them. They can even charge them with trespassing if they don't leave.
Yes.
Yes an 18 year old can because none controls you exsept you! X