Yes, as long as he/she has documents proving authority to work in the USA.
Not in any of the US states. Not legally.
Yes. 19-year old people can date anyone they want to date anywhere in the US.
yup
With parental consent this is possible ion several states.
In the US, a 19 year old does not need parental permission to do anything as far as the law is concerned (unless the 19 year old is under the care of a guardian for mental incapacity, or something).
A 19 year old is an adult. It is up to him/her if they want to be adopted.
The 16 year old will have to have parental permission. And they will have to meet all the requirements for immigration, which may require them to be older in order to do so.
yes you can if are at least 18 years of age!
Not in the US. You must be 21 to buy a submachinegun
In most places in the US, yes. The citizenship does not matter. It will not immediately grant US citizenship to the immigrant.
There is nothing technically wrong with this relationship, it is legally permitted in most if not all states of the US. Family members, especially parents of the 19 year old, may feel this is not a good couple.
There is no law prohibiting dating in any state of the US. The age of consent in Kansas is 16.