I think your questions are both OK. Your only mistake is that you mention the Present Perfect Progressive (also called the Present Perfect Continuous) but you don't use it.
When inquiring about periods of time regarding activities that still occur/are still true (and are not completed), the right approach in English is always a Present Perfect tense. Whether that be Continuous (+ing) or Simple (+ past participle) (and if the action is completed, but we don't know when), depends on the verb. State verbs (like "be" in your first example) can only be employed using Present Perfect Simple, whilst action verbs (like "study" in your second example) can be employed in PPS/PPC. Using PPC gives your sentence/question that emphasis of "repeated/continuous" activity, but is not mandatory.
So:
How long/How many years have you studied English?
Is just as worthy as:
How long/How many years have you been studying English?
(The same applies to your first example too)
Which brings us to your question of how to phrase your query if you wish to receive an answer using a specific "time reference" (ie "years" in your example). Generally speaking, the native English speaker will likely not worry about the "time" part of the question too much, leaving the listener to respond in the most logical way. In your example, this would likely be in years, or possibly:
Since I was 5.
Of course, sometimes specificity is needed or desired as in your question. If you don't want "since I was 5" type answers, then you need to "lead" the listener, by encouraging them to respond according to the "time" part of the question you use.
How many years? = For x years
How many days? = For x days
Etc.
Consider this last example of a situation where a specific (maybe overly?) response is needed.
A manager has to enter a candidate's information into the following box on their computer during a job interview: Years of higher education studies completed: [ ]
The manager will obviously require a response in years, and so will need to ask his question accordingly:
How many years of higher education studies have you completed?
Note the use of PPS for the "finished action".
Or, if the candidate is still studying:
How many years have you been studying in higher education?
Naturally, my examples work just as well with a more general "time query" (ie "How long?") if the answer doesn't need to be specific.
I hope that answers your question fairly well. Maybe I went into too much detail on PPS/PPC and confused you (I hope not!). As a final observation, I think your first question reads more naturally without "for".
In my observations, it depends on the context of the situation.
Most of the time (in my opinion, from my experience), however, if they use the word 'would', they are likely upset, uncommonly perplexed, or emotional because you asked 'that' (especially if they say 'Why would you even ask that?' or if they put uncommon emphasis on 'Why', 'that', or 'would'). They may just be slightly emotional, or find it funny that you asked (pay attention to see if they're smiling or laughing). Maybe you asked something unusual that a native English speaker normally wouldn't say (which may or may not have anything to do with language, and everything to do with culture). Listen to their tone of voice, as it may convey more meaning than the words they say.
If they're calm and collected, however, they might just be more inquisitive and not at all offended, alienated, or tickled by what you said.
Arguably, they could mean the same things I highlighted above if they said 'did' instead of 'would' (especially if they add emphasis somewhere), but I think that's less common (although it still happens).
In another light, 'would' isn't limited to the past, and it's not limited to something that actually happened, while 'did' is. You could ask someone why they would do something they're hypothesizing about, but you can't sensibly ask someone why they did something they're hypothesizing about unless they've actually done it:
- Why would you build that time machine [you're thinking about building (which time machine you've never built to date)]?
- Why did you build a snowman [last winter]?
- Why would you say that [thing you're thinking about saying, but haven't actually said]?
If you actually did 'ask that' and they still say 'would', they might be thinking it's something you're likely to ask again, or be in a habit of asking (but they might not be thinking either of those things).
Arguably, the two phrases are interchangeable with pretty much the same meaning in some contexts:
- Why would you ask that [thing you asked in the past]?
- Why did you ask that [thing you asked in the past]?
Although the words 'would' and 'did' have different meanings, the sentences as a whole pretty much mean the same thing here in some contexts. Saying 'Why would you ask that' seems to me that it would solicit a variety of reasons, potentially, while 'Why did you ask that?' seems to me that it would only solicit one reason (the specific reason you had for asking). 'Why would you ask that?' seems more polite in my mind, because it allows people to answer truthfully without forcing them to say their true intent in that specific circumstance; however, if you know they really only want to know that reason, you probably shouldn't let them think that was it if it was just a reason you might have, but didn't use.
Best Answer
The difference, when there is one, is about being polite:
Would you like some milk in your tea? [a polite way to ask the question]
If you know the person and the person is your friend, you can say:
Do you want milk in your tea?
It really is as simple as that.
Please note the grammar point below: Do you want we have the meeting in this room?" "Do you want we have lunch in that restaurant?"= To be grammatical, those need to be changed to:
Please note: to want [someone] to do something is one expression.
Another is: Do you want x? Do you want lunch now?