Yes, "you" can be either singular or plural.
The conventional way to ask this question would be: "What are your names?" If you were asking only one person for his name you would day, "What is your name?"
(There is a small possible ambiguity if the person has more than one name. Like if someone was a criminal who regularly used fake names, the policeman might ask him, "Okay, so what are ALL your names?" Perhaps I should clarify that while people regularly have first, middle, and last names, we still refer to all of this as "your name". People say, "My name is Fred Smith", not "My names are Fred Smith.")
I'm not sure why you said "actual names" in your examples. The word "actual" would only be meaningful in the sentence if it is necessary to contrast with some non-actual name. I guess if you were asking a group of actors, you might want to make clear that you mean their real names and not the names of their characters in the show. Or if there was a possible ambiguity whether you meant their log-on id's to the computer system versus their real names. But normally, you just say "name".
As to your examples:
1.What are the actual names of yours?
Grammatically correct, I suppose, but awkward. A fluent speaker would be more likely to say, "What are your actual names?"
2.What are the actual names of you all?
Acceptable for casual speech, especially in the southern U.S., but would likely be questioned if used in formal writing.
3.What are the actual names of your?
No. "Your" is a possessive and does not fit here. It is an adjective with no noun to modify. You could say, "What are the actual names of your friends?", etc
4.What are the actual names of you people?
Fine for casual speech, but a little awkward. Probably would not be used in formal speech. Also, the phrase "you people" can be considered rude. It implies that they are members of a class that is different from yours and presumably inferior. I'd avoid this phrase except when you want to indicate anger or disdain. "You people get out of here!" Or, "I'm tired of putting up with you people."
5.What are the actual names of all of you?
That's perfectly good and grammatical. It's more long-winded than necessary, which may or may not be a bad thing.
These are called subject questions (as your first example) and object questions (as your second). Here we are talking about "do", so this is present simple and past simple tense. Let us take one example:
Paul wants to speak to him.
1) If we want to know who "him" is, "him" is the object and the question we will ask is an object question. There will be an auxiliary verb, which will come between the question word and the subject:
Who does Paul want to speak to?
2) If we ask a question about "Paul" (the subject), however, it will be a subject question, and then all we need to do is substitute the subject with a question word:
Who wants to speak to him?
Further reading with examples: in this grammar book
3) It is possible to add an auxiliary verb in subject questions, that has already been discussed here. To sum it up, it adds emphasis, as in:
A: Who wants to speak to him? Jack?
B: No.
A: Jim?
B: No.
A: Well, then who **does** want to speak to him?
More examples of that can be found in the link.
Best Answer
Yes, these are all equivalent to the ordinary questions formed with subject/auxiliary inversion.
The question mark indicates the rising pitch at the end which distinguishes your sentences from ordinary declaratives.
Note that these 'declarative' questions are only used "echoically": repeating the substance of something that has been said to get confirmation of what you have heard.