You said "if we use the agent, the sentence becomes passive voice". I have to disagree. In every one of your examples, the subject of the verb is the patient of the action. Regardless of whether the agent is mentioned, those statements employ the passive voice.
You're asking how to distinguish something that doesn't need to be distinguished. The question of passive vs. active voice is completely different than the question of stative vs. dynamic verbs -- in the same way that the question of how curly your hair is happens to be completely different than the question of how dark your hair is.
In an active voice construction, the subject causes the action. In a passive voice construction, the subject receives the action. It's easy to see that all of your sentences are passive voice constructions because its easy to find the active voice equivalents:
Someone parked the car.
Something increased your work volume.
Someone arrested him.
and so on.
Although the stative vs. dynamic distinction exists in English semantics, it isn't present in English grammar. One rule of thumb is that stative verbs do not work well when employing the continuous aspect. For example, "I am knowing the answer" is a poorly-formed sentence because the verb to know is stative. It seems that every one of your passive voice examples uses a dynamic verb.
One car was being parked outside the gate when I left.
Your work volume is being increased during the holidays.
He was being arrested while I calmly walked away.
and so on.
A stative verb can be used in either the active or the passive voice:
My manager knows me to be an excellent employee.
I am known to be an excellent employee.
A dynamic verb can be used in either the active or the passive voice:
I parked the car outside the gate.
The car was parked outside the gate.
So, how do you distinguish between passive and stative? You don't. You distinguish between active and passive. You distinguish between dynamic and stative. You do those two things separately. They are not related to each other.
Now, as to your follow-up question, let's use the dynamic verb to park in the passive voice and indicative mode:
The car was parked -- past tense, indefinite aspect
The car is parked -- present tense, indefinite aspect
The car will be parked -- future tense, indefinite aspect
The car had been parked -- past tense, perfect aspect
The car has been parked -- present tense, perfect aspect
The car will have been parked -- future tense, perfect aspect
Does the meaning change? Yes. Aspect carries a different kind of meaning than tense, but both aspect and tense carry meaning. Tense has to do with location in time. Aspect has to do with a relationship with time. Often tense and aspect are taught as a single, combined thing, but I find them easier to understand when they are examined as separate properties.
Changing the aspect does not change the tense. Changing the aspect does not change the voice. Changing the aspect does not change the nature of the verb, whether stative or dynamic.
Because the perfect aspect has an explicit relationship with time, it makes the most sense when the time frame is also made explicit, as in "The car has been parked there for several weeks" or "The car had been parked there for a month before anyone noticed it."
Whether a verb is stative or dynamic has very little impact on English grammar. Certain verb forms don't make sense for stative verbs, and that's about it. The properties of voice, tense, aspect and mode have a great deal of impact. Changing any one of those requires changing something about the verb's form.
Let me see if I can clearly summarize all of that.
- Which of the example sentences are passive voice? All of them.
- Which of them are indicative sentences? All of them.
- Which can be interpreted as having a participial subject complement? All of them.
- Which are stative? None of them.
Most of those are unrelated items. One pair is an identity. The passive voice construction is a subset of the participial subject complement construction.
I had it taken recently is definitely NOT in the past perfect!
I took it recently = You did it yourself.
I had it taken recently = You asked someone to do it for you.
(Both sentences are in the simple past.)
BACKGROUND
The name "past participle" is a rather unfortunate one. It's one of the sources of confusion in English grammar learning. This is mainly because the English passive voice and the English perfect use the same form of verb, i.e., the past participle form of a verb.
I quoted an entry in a grammar book once, in this answer (follow the link for more information). To demonstrate this point with the same examples, I'll discuss them, briefly, below:
Past participles are used to make both passive verb forms and active perfect tenses. Compare:
(1) He was calling. (active - past progressive)
(2) He was called. (passive - simple past)
(3) He has called. (active - present perfect)
In (2), called, the past participle form of call, is used after the auxiliary verb BE in its past form, was. A main verb in its past participle form after BE indicates that the clause is in the passive voice. In this example, someone called him -- he was called -- he was called by someone.
In (3), called, again the past participle form of call, is used after the auxiliary verb HAVE in its singular-present form, has. A main verb in its past participle form after HAVE indicates that the clause is in a perfect tense, in this case the present prefect. In this example, let's say that someone ask you, "Jack told me he'd call the lieutenant today. Has he called?" and because Jack has done so, you may reply, "He has called."
BACK TO OUR QUESTION (BARE PASSIVES, e.g., have something done)
The confusion caused by your sentence, I had it taken recently, is perfectly understandable, because in this sentence, had is the main verb, NOT an auxiliary verb. This is a special use of have, as defined in the Macmillan Dictionary in definition 14, like this:
have
[transitive] [never passive] to arrange for something to be done or for someone to do something
have something done: The place is looking much better since they had it redecorated.
She wanted to have her portrait painted by a famous artist.
have someone do something: I’ll have someone bring your luggage up right away.
So, I had it taken already means that you asked someone to take the photo, and the photo had already taken.
One way to explain the syntax of have something done is to treat it as a bare passive that complements the main verb (typical verbs of that allows bare passive complements are have, get, order, and other sense verbs such as see).
Best Answer
You are right that in passive voice we use was (or any other form of the verb be) and a past participle. This means we can create phrases like these:
You will notice that both of the sentences above contain a relative clause (i.e. that was eaten/who was taken), that we can reduce to remove the pronoun and be verb form. We do this to be more economical in our expression. That means the following sentences are equally valid:
Your mistake was to not add "who/what" to describe the boy.
Some more information on participle clauses can be found here on the BBC.