What's wrong with: "Nós não falamos nunca"
It would be weird once prepositions are usually placed before verbs. Also, never is used in affirmative sentences to make them negative. So, you can't use não and nunca this way.
I'm not sure why "nós falamos nunca" is incorrect?
Perhaps: Nunca nos falamos.
this is the present perfect in english, is conversamos in the past, signifying the same feeling as the PresPerf in english?
Yes, most of time we translate "present perfect" as simple past in Portuguese...
This sentence can also be construed as present tense, showing the condition of having never spoken continues. But there is no distinction in the verb forms.
How do use the "falado" tense for this sentence. I tried "nos nunca ha falado" but apparently that's no good
Ter + falado