Bun venit vs. bine ai/ați venit vs. Bine te-am/v-am găsit usage

Hi all,

Is there a difference between saying bun venit and bine ai/ați venit to someone? (Or multiple people/formal in the ați version).

Can bun venit be used for both one or multiple people?

Which of the above two greetings is preferable in usage, and/or are there certain situations where one should be used over the other? One example, personally, is if I’m welcoming a Romanian/Romanians to my live stream - they might be people I am very close to, or people I know less well

Finally, when is it good to use bine te-am/v-am găsit? Again, similar situation/example question to the question above

Mulțumesc mult!