It was my understanding that Russian uses these in corresponding pairs
То,что --- pronoun, pronoun
Тогда, когда --- adverb, adverb
Так, как
там, где

Yesterday I realized I couldn't convey "...about how they..." in Russian, trying things like "о так, как", and knowing that was wrong. I moved on, confused, at the time, but I just saw what seems to be the missing key here. I had believed that it would be a little conceptually strange to mix them but I guess it's actually crucial and incredibley useful.

По-рууски: Подобно тому, как это говорят русские.

"То, как" seems to be verified

1) Ive only seen this example, so I want to make sure this really is a thing, and moreover, what do other combinations come out as?

pronoun, adverb
то, когда ?
то, где ?

Я рассказал ему о том, когда она умерла.

I also have to ask, why am I considering то so special. I suppose it is the only one that is an actual pronoun, and declines, except for что. 2) This leads me to ask,what would these phrases mean in context, or are they at all valid:

adverb, pronoun
тогда, что/чего/etc.
там, что/чего/etc.

Шли мы туда, о чём бабушка говорила.

(trying not to confused что the conjunction with что the relative pronoun, the latter being the topic of interest here)

These things are hard to uncover and understand as an English native because we, in most casual speech, bundled and package both halves into one question word, and throw one preposition to the end. Learning how to reverse this process is fundamental for learning Russian I feel.