Be going to be doing.

Yeah, not a speck of difference in meaning that I can see. For grammatical reasons, you might pick one over the other, depending on context, but they mean the same thing.

Everything you wrote as examples are flawless sentences, as far as I can tell. But it would be OK to phrase it differently, for example:

"We are going to invest in a new market." You would use invest (not" investing") when you put it his way, that's all.

To my way of thinking this is better. Fewer words (leaving out "be" which adds nothing).

In either case it's clear that you are stating your intentions about acts to be taken in the future.

The more distant that "future" might be, the more I might consider "going to be," rather than simply "going to."

I guess I should add that "be" is necessary when you're talking about some future status, as opposed to intended actions.

For example: By the year 2020 we are going to be debt-free.

Layman, thanks for taking your time to answer the question. Be frankly, I'm hesitant to use "be going to be doing" thanks to the fact that this kind of form can not be found in all my grammar books, many of which happen to be written by British and American educators.

Layman, good luck to you.

Quick name change.

I wouldn't have used this ID to log in if I hadn't forgotten the password of my original ID, which is rosenberg, roger. I may have written it down in a notebook. Anyway, take care, roger.

Of course not. No one would use the phrase I bolded above, at least not in the context of the numerous examples you gave. That's not the question I was responding to, if it was a question.

That said, there would be nothing wrong with saying, for example:

"I'm going to be doing his tax returns for him in April."

But, not, of course, "I be going to be doing...."

Look for the 'future continuous'. It comes in two different forms: "will be doing " and "be going to be doing." Future continuous forms are usually interchangeable.

Future continuous with "will"

[will be + present participle]

Examples:

You will be waiting for her when her plane arrives tonight.
Will you be waiting for her when her plane arrives tonight?
You will not be waiting for her when her plane arrives tonight.

Future continuous with "be going to "

[am/is/are + going to be + present participle]

Examples:

You are going to be waiting for her when her plane arrives tonight.
Are you going to be waiting for her when her plane arrives tonight?
You are not going to be waiting for her when her plane arrives tonight.

It is possible to use either "will" or "be going to" to create the future continuous with little difference in meaning.

Notes here:

http://www.englishpage.com/verbpage/futurecontinuous.html

I think "going to" is for informal conversational use.

Some of your sample sentences could have used a form of "plan" or "intends."

Our firm plans (or is planning) to expand next year.

Informally: She is going to have a fit when she finds out about his cheating.

Yeah, and those choices would actually be better than "going to," eh?

Of course, in everyday vernacular, we would all contract that to "gunna" or, better yet, "Imma" as in "Imma invest in some good ****."

A study in total confusion.

That is false, Punkey.

And you haven't even made it clear if you mean the periphrastic modal 'be going to' or the simple verb 'going' + preposition.