1. You could, but the meaning is not the same. When only comme is used, it describes the way an action is done, and it always compared to doing the same thing. Here, speaking.

   [Elle court] (A) comme si [sa vie en dépendait.] (B)

   A and B are not the same kind of action. B gives a reason that could explain the manner A is done.

   [Elle me parle] (A) comme [elle aurait récité une leçon.] (B)

   A and B are the same type of action. She speaks to me in the same way that she would recite a lesson. The meaning is very different.

   (Every time si is between parenthesis I assume it’s omitted.)

2. Yes.

3. No. When you don’t use si you can’t use imparfait. You sentence would mean that she did recite her lesson earlier, and she spoke the same way. You lose the hypothetical part if you do that.

4. I think you forgot the pronouns, but you’re right in your first assumption.

5. I’m not sure about this one. I think it can also mean “as if she was ill (at the time)”

6. I already answered, it means she did recite a lesson, previously. (So your first assumption, but not hypothetical.

7. In the case of G2, it means “at the time she was speaking”.

8. That basically means the same thing as G2, but it’s a different style. It’s less elevated than the original. It means she has an habitual way of reciting lessons, and she spoke in that way.

9. It’s kinda weird to use present tense here. It’s not ungrammatical, but it implies she’s still living in present day. You can say that if you speak about how someone you know spoke (during certain period of time to justify imparfait) some time before. That wouldn’t be used in such a book.

   It’s common to use present in these form, for things more likely to happen than those we use conditionnel with, but it has to be consistent with the tense of the story.

10. Nope, if you use present here, you’ll use indicative. Famous example:

    Moi la mer elle m’a pris comme on prend un taxi (Renaud, Dès que le vent soufflera)

I’ll try to answer you in the best possible way even though I don’t know every grammatical rules :

1 – It may be grammaticaly correct but it’s ugly and wouldn’t be used. Plus it’s important for you to understand that old french is spoken here , it’s oudated. “Comme si” is more an up to date expression so it’s an other reason why it doesn’t match.

2 – Yes it is

3 – I don’t realy know what to answer about “comme” and the context because it’s old french , the actual version would be “comme on récite une leçon”.
What you came with is correct but it’s “ugly” , if you want to speak in the past : “comme si elle récitait” . Using the “Imparfait”here because it’s in the past but refering to smth not over yet.

4 – First , you forgot “elle” : “comme si elle avait été malade”. It’s is “plus que parfait” , used to describe something which came to it’s end , which is over. So she’s speaking as if she were ill , but it was over at the time she speaks about it.

5 – Same about “elle here” . Then , it is “Passé antérieur” , quoting wikipédie : “Le passé antérieur exprime une action antérieure à un passé simple” which means it refers to something over which took place before somthing you would talk in “Passé simple”.

6 – Here it means that she spoke as if she were then (i.e. contemporaneously with speaking) reciting a lesson , i can tell because of the use of “imparfait” which as I told before is used to speak of an action which took place in the past but is still going at the moment you speak about it.

7 – It’s complicated. Here it means that she spoke as if she were then (i.e. contemporaneously with speaking) reciting a lesson but I can’t realy explain why. (Maybe i could , but in french , and I don’t know if it would be ok with you)

8 – Yes , it’s correct.

9 – Something here is wrong , the exact formulation using the present would be “comme on récite une leçon”

10 – Mi is correct with the “si” , not without. Without the “si” it’s a comparison : she speaks like she’s ill.
You’re right on the meaning of the sentence.

Nonetheless M0 isn’t correct at all. “Le subjonctif présent exprime une action incertaine, non réalisée au moment où nous nous exprimons.”
You can’t speak about smth taking place in the present in way that discribes smth which didn’t take place yet , and may take place in the future !

I hope it helped you , sorry if my english fails me , i’m like you : still learning ! 😛

To answer more generally: comme si + indicative here would together replace the conditional (and yes, eût is indeed conditionnel passé). In this regard it’s much the same as in English:

…as if she had been reciting a lesson. / …as if she were reciting a lesson.

vs.

…as she would have recited a lesson. / …as she would recite a lesson.

Is the meaning of these two statements the same? Practically speaking, yes. The "condition" of the conditional may be paraphrased "If it were the case that…"

Indeed, one often specifies the condition for the conditional in sentences of this familiar construction of si + imparfait (or plus-que-parfait) followed by the conditional:

S’il avait acheté le chat, on entendrait des miaulements.

Which can also be reversed:

On entendrait des miaulements s’il avait acheté le chat.

Because we don’t have to spell out our line of thinking most of the time, the condition can be implicit or tautological:

…as she would have recited a lesson if she were reciting a lesson.

In such cases, it’s usually omitted for obvious reasons:

…as she would have recited a lesson if she were reciting a lesson.

However, with si doing the job of distancing the clause from reality in order to make a comparison, you could equally well leave the other half and still have it be hypothetical.

…as she would have recited a lesson if she were reciting a lesson.