1. The door won't open.

2. She won't open the door.
(Does 'won't' mean 'volition' of the subject? Or does each sentence have a simple future tense?)

3. She will open the door.
3-1. She intends to open the door.
3-2. She is going to open the door.
(Does #3 mean #4 or #5? Simple future tense or volition?)

4. She shall open the door.
5. I will have her open the door.
6. I will let her open the door.
7. I will make her open the door.
(What does #4 mean, #5, #6 or #7)

1 is simply future tense.

2 involves volition (she refuses to), yes.

3 is simply future tense.
3-1 states volition in "intends"
3-2 is simply future in sense.

4, 5, and 7, have the implication of "forced to" in them.

6 has the idea of being allowed to, but not forced to.

1. In the sentence "The door won't open," the word "won't" is a contraction of "will not." It indicates a negation in the future tense. It suggests that the door is unable or unwilling to open.

2. In the sentence "She won't open the door," the word "won't" is also a contraction of "will not." In this context, it indicates a negation of the subject's volition or willingness to open the door. It implies that she refuses or is reluctant to open the door.

3. The sentence "She will open the door" expresses a simple future tense. It suggests that at some point in the future, she is expected to open the door willingly or by her own choice.

3-1. The sentence "She intends to open the door" suggests that she has made a conscious decision to open the door. It implies her volition or resolve to do so.

3-2. The sentence "She is going to open the door" also indicates a future action. It suggests that she has a plan or intention to open the door, although it does not explicitly imply her volition.

4. The sentence "She shall open the door" is less commonly used in modern English. It can denote a sense of obligation or inevitability, potentially suggesting that it is required by a rule or duty.

5. The sentence "I will have her open the door" implies that the speaker, "I," will make sure that she opens the door. It emphasizes the speaker's intention or control over the situation, potentially overriding her volition.

6. The sentence "I will let her open the door" indicates that the speaker will allow or permit her to open the door. It suggests that the speaker has control in granting permission, but it leaves the choice up to her, implying her volition.

7. The sentence "I will make her open the door" suggests that the speaker will force or compel her to open the door. It indicates a lack of volition on her part, as she may not have a choice in the matter.