Understanding use of "conocer" and "saber" in "knowing someone"
So... I'm trying to understand different nuances of "knowing someone" and when to use "conocer" vs. "saber". Please review text below and tell me what I got right and what needs improvement.

Simplest situation:

Do you know Juan Gabriel? (i.e. do you know him personally?) - ¿Conoces a Juan Gabriel?

But... what if I don't expect that you know him personally? What if I'm just trying to find out if you have ever heard of him? That is, do you know that he is the most famous Mexican singer? Do you know his songs?

Do you know who Juan Gabriel is? - ¿Sabes quién es Juan Gabriel? (from Google Translate)

Or... is "conocer" still better here? ¿Conoces el cantador mexicano, Juan Gabriel?

Finally, let's forget Juan Gabriel the singer. Imagine there's a bunch of children in a classroom and you want to know which one is Juan Gabriel. How would you ask this?

Do you know which (child) is Juan Gabriel? - ¿Sabes cuál es Juan Gabriel? (from Google Translate)

But... my instinct is to say ¿Sabes lo quién es Juan Gabriel?

Question

Understanding use of "conocer" and "saber" in "knowing someone"
So... I'm trying to understand different nuances of "knowing someone" and when to use "conocer" vs. "saber".  Please review text below and tell me what I got right and what needs improvement.

Simplest situation:

Do you know Juan Gabriel?  (i.e. do you know him personally?) - ¿Conoces a Juan Gabriel?

But... what if I don't expect that you know him personally?  What if I'm just trying to find out if you have ever heard of him?  That is, do you know that he is the most famous Mexican singer?  Do you know his songs?

Do you know who Juan Gabriel is? - ¿Sabes quién es Juan Gabriel? (from Google Translate)

Or... is "conocer" still better here?  ¿Conoces el cantador mexicano, Juan Gabriel?

Finally, let's forget Juan Gabriel the singer.  Imagine there's a bunch of children in a classroom and you want to know which one is Juan Gabriel.  How would you ask this?

Do you know which (child) is Juan Gabriel? - ¿Sabes cuál es Juan Gabriel? (from Google Translate)

But... my instinct is to say ¿Sabes lo quién es Juan Gabriel?

Answer

saber is general knowledge and conocer is personally know someone or some place (have been to).
particularly for people here's some examples that could help you out.
*(en una conversación con presentaciones) a: ¿se conocen? b: si, ya nos presentó ana. (a: do you know each other? b: si, ana ya nos presentó.
*conozco a juan del colegio. (I know juan since school)
*a: ¿conoces al nuevo gerente? b: sí, o sea, no lo conozco personalmente pero se quien es. (a: do you know the new manager? b: i do, i mean, not personally but i know who he is.
*¿alguna vez has conocido a alguien famoso? (have you ever met a famous person?)
*a: ¿sabes quién es brad pitt?=¿ubicas a brad pitt? (do you know who brad pitt is?)
b: ¡sí! ojalá lo conociera en persona, jaja. (yes! i wish i knew him in person, haha)

hope this helps, saludos!

Answer

Hi Richard!
The answer is more simple than you think.
 We use the verb "saber" for :
*Facts
*Information 
*Learned Skills 
Saber is also normally used after an interrogative pronoun such as quién, cuál, qué, dónde, etc. just like in the examples you provided in your question: ¿Sabes quién es Juan Gabriel?
we normally don't use the verb "conocer" with these interrogative pronouns, if you'd say, for example, "¿Conoces quién es Juan Gabriel?" would sound a little unnatural and strange. So, ¿Conoces a Juan Gabriel? sounds much better.
and finally, we use the verb conocer for:
*People (followed by th personal "a")
*Places
*Things
I hope you find this information helpul!

Answer

Saber - información

Conocer -  a alguien o algo

No sé bien las matemáticas. 
París es una ciudad por conocer.

Answer

Hello Richard,

When you want to know if someone knows Juan Gabriel you can say; 
¿Sabes quién es Juan Gabriel?
¿Conoces al cantante Juan Gabriel?
¿Sabes qué canciones canta?
¿Conoces sus canciones?

Imagine there's a bunch of children in a classroom and you want to know which one is Juan Gabriel.  How would you ask this?
Do you know which (child) is Juan Gabriel? - ¿Sabes cuál es Juan Gabriel? (from Google Translate) THATS IS CORRECT  BUT IF YO WANT TO ASK ALL THE CHILDREN AT THE SAME TIME WHO IS JUAN GABRIEL THEN YOU MUST SAY;
¿QUIÉN ES JUAN GABRIEL? OR ¿QUIÉN DE VOSOTROS ES JUAN GABRIEL?

But... my instinct is to say ¿Sabes lo quién es Juan Gabriel? IT IS ALSO CORRECT WITHOUT "LO"
¿SABES QUIÉN ES JUAN GABRIEL? = ¿ DO YOU KNOW WHO IS JUAN GABRIEL?

More examples: 
¿Conoces el libro "The Lord of the Rings"? = ¿Sabes cuál es el libro "The Lord of the Rings"? 
¿Sabes tocar el piano? , ¿Sabes cómo se hace un pastel? (in this case we can´t use "conocer")
No conozco la capital de Francia. (that means: I've never been there) 
No sé cuál es la capital de Francia. (that means: I have no idea what is the Capital of France)

I hope to be useful
See you