Can I bring my service dog, who is a very small breed, and weighs 10lbs. not only there, but to visit someone who was just admitted bc of a MVA ? Mind you, I'd be arriving later than normal visiting hrs. due to the time he arrived and was admitted.

Yes

Yes . All you have to say is they are a service dog security isnt supposed to question it i work in the ER

It is a healthcare facility. Service dogs are permitted if they are trained for a specific task. Emotional support animals are not permitted. Keep in mind that per NYS public health law, they are not permitted in ICUs, surgical prep/recovery areas or the maternal wards, regardless of the purpose the animal serves.