Se que la persona me va a entender, pues no quiero parecer estupida ni bastante formal... Cual es la manera mas correcta, pero no muy academica?

Gracias!

La primera opción definitivamente es incorrecta.
La segunda es formal
la tercera es más cómun.
La cuarta puede ser correcta pero no en esta situación.

Espero haberte ayudado.

Pd. Soy un estudiante de inglés, nativo de habla hispana (México)

"We have never spoken/conversed before."Since this is a slightly formal way to say it in English, you get a slightly formal way to say it in Spanish

Nunca hemos hablado/conversado antes.

Recuerda también que hay que traducir "before" también, aunque la frase se entiende sin el "antes".

Also, as English_student mentioned, the first option is wrong. Conversar is not a reflexive verb.
:)

Muchissimas gracias!

Espero que pueda ayudarles en el futuro!

Espero que pueda ayudarles en el futuro!
Seguramente podrás! ;D

I know conversar isn't a reflexive verb, but aren't verbs sometimes used in that manner to signify "with each other" or something of the sort? Maybe?

I know conversar isn't a reflexive verb, but aren't verbs sometimes used in that manner to signify "with each other" or something of the sort? Maybe?
That's an excellent question. And I don't really have an answer. Here's some examples

Hablaron de un tratado de paz - They spoke of a peace treaty
Se habló de un tratado de paz - A peace treaty was mentioned
Se hablaron de un tratado de paz -

That last example-- (1) Is that correct Spanish/ is it used by native speakers? (2) What would it mean exactly? "They spoke about a peace treaty" "The two of them discussed a peace treaty"?

As I go over this in my mind, I think you can use it, for example "Mi hermano y mi papá no se hablan", which would mean "My brother and my dad are not on speaking terms".

So I guess the answer is yes :)

That's an excellent question. And I don't really have an answer. Here's some examples

Hablaron de un tratado de paz - They spoke of a peace treaty
Se habló de un tratado de paz - A peace treaty was mentioned
Se hablaron de un tratado de paz -

That last example-- (1) Is that correct Spanish/ is it used by native speakers? (2) What would it mean exactly? "They spoke about a peace treaty" "The two of them discussed a peace treaty"?

As I go over this in my mind, I think you can use it, for example "Mi hermano y mi papá no se hablan", which would mean "My brother and my dad are not on speaking terms".

So I guess the answer is yes :)That's a bit over my head, I'm still working on the reflexive verbs and they make my brain mushy.