Learn English – “Are also” or “also are”

No, abstract nouns and adjectives are two different things. Anger is an abstract noun, while "angry" is and adjective. "Length" is an abstract noun, while "long" is an adjective.

While specific words can be categorized into different parts of speech depending on how it is used in a sentence, specific parts of a particular sentence can only be categorized as one part of speech. For example, take the word "love".

A mother's love is eternal. (here love is an abstract noun) I love pizza. (here love is a verb)

Yes, this is a mistake. I can see 6 Google results for "we are also be talking about", but four of those are from the same (possibly Chinese?) source, one also looks to be Chinese, and the remaining link is an automatically-generated transcript from a video, and therefore cannot be trusted to be correct.

The correct phrasing is "But we are also talking about...". The extra "be" is wrong because the verb "to be" is already present in the form of "are".

To answer your remaining questions: "we will also be talking about" is correct because "will" is necessary to signal that we are talking about the future. Other tenses don't use "be" like this, so "we were also be talking about" is incorrect.