Say/tell/speak/talk questions

Hello,

I would like to ask you to help me clarify some points regarding the use of say/tell/speak/talk.

#1:

I don't know what his name was, he didn't say.

That is correct. Can I also say:

I don't know what his name was, he didn't tell.

Or is it incorrect because the thing being said is just a name? What about:

I don't know what happened, he didn't say.

I don't know what happened, he didn't tell.

Both seem equally correct to me.

#2:

The President spoke to the people on TV today.

That is correct. Can I also say:

The President talked to the people on TV today.

I know that in such a formal context, the verb speak is the natural choice but still, would it be possible to use the verb talk?

#3:

I need to talk to the manager.

I need to speak to the manager.

Both seem correct to me, yet - in my opinion - the first is less formal and the latter might emphasize that I need to discuss something really important. Am I right there?

#4:

We talked about girls in the pub.

We spoke about girls in the pub.

Am I right here if I say that "spoke" sounds a bit odd here as the nature of the discussion is very informal?

#5:

If I saw a mouse who could speak, I would say:

He/she speaks.

Can I use He/she talks as well? I heard it in the latest Chronicles of Narnia film.

#6:

She speaks quickly.

She said it quickly.

She told the story quickly.

All are correct in my opinion, but in the former she speaks quickly all the time and in the last two examples, she spoke quickly just in that single occasion. Correct?

Thanks for your answers!