Aunque no siempre estoy de acuerdo, intento debatir sin enfadarme y argumentar con calma.

Aunque means although / even though. It introduces a contrast:

• Aunque no siempre estoy de acuerdo = Although I do not always agree
• intento debatir sin enfadarme y argumentar con calma = I try to debate without getting angry and to argue calmly

So the overall idea is: there is disagreement, but despite that, the speaker tries to stay calm and reasoned.

Because estar de acuerdo is the fixed Spanish expression for to agree / to be in agreement.

• estoy de acuerdo = I agree / I am in agreement
• no estoy de acuerdo = I do not agree

You do not say soy de acuerdo.

This is just how Spanish expresses the idea. Even though English uses to be, Spanish specifically uses estar in this expression.

Yes, aunque can be followed by either indicative or subjunctive, depending on meaning.

Here, aunque no siempre estoy de acuerdo uses the indicative because the speaker is stating something real and known: they really do not always agree.

• Aunque no siempre estoy de acuerdo... = although I do not always agree
• Aunque no siempre esté de acuerdo... could also exist, but it sounds a bit less direct/certain and more like a general or concessive framing

So in this sentence, estoy is natural because the disagreement is presented as a fact.

No siempre means not always.

It is important not to confuse it with never:

• no siempre = not always
• nunca = never

So no siempre estoy de acuerdo means:

• sometimes I agree
• sometimes I do not

It does not mean the speaker always disagrees.

That word order is the most natural one here:

• no siempre estoy de acuerdo

It is the normal way to say I am not always in agreement.

Spanish often places adverbs like siempre, nunca, a veces, etc. before the verb or around it, and in this case no siempre estoy... sounds very natural and idiomatic.

Because intentar can govern more than one infinitive.

Here the structure is:

• intento debatir
• (intento) argumentar

The second intento is omitted because it is understood. This is very common in Spanish.

So:

• intento debatir sin enfadarme y argumentar con calma

means:

• I try to debate without getting angry and to argue calmly

You could repeat intento, but it is not necessary.

After sin, Spanish very often uses an infinitive when the subject is the same.

So:

• sin enfadarme = without getting angry

This literally follows the pattern:

• sin + infinitive

Examples:

• sin hablar = without speaking
• sin comer = without eating
• sin enfadarme = without getting angry

If the subject changed, Spanish would usually use a different structure, often sin que + subjunctive.

Because with an infinitive, reflexive pronouns are attached to the end.

The verb is enfadarse = to get angry

So:

• enfadarme = to get angry / to become angry
• literally: to anger myself, though that literal translation is not how we say it in English

Compare:

• Me enfado = I get angry
• sin enfadarme = without getting angry

With a conjugated verb, the pronoun usually goes before:

• me enfado

With an infinitive, it attaches to the end:

• enfadarme

It is very common in Spain, yes.

In much of Latin America, learners will also often hear enojarse for to get angry. Both are understood, but for Spanish from Spain, enfadarse is a very natural choice.

So for a Spain-focused learner, this sentence sounds very appropriate.

They are related, but not identical.

• debatir = to debate, discuss an issue, exchange views
• argumentar = to argue in the sense of presenting reasons or arguments

So in this sentence:

• debatir focuses on the act of discussing
• argumentar focuses on expressing and supporting your point logically

Using both gives a fuller idea: the speaker tries to take part in debate and also make arguments calmly.

Because discutir can sometimes sound more like arguing or quarrelling, especially in everyday use.

• debatir often sounds more neutral, reasoned, or formal
• discutir can suggest conflict

Since this sentence is about staying calm and reasoning well, debatir fits especially well.

Both are possible, but con calma is usually more natural and common in everyday Spanish.

• argumentar con calma = to argue calmly / with calm
• argumentar calmamente is grammatically correct, but it sounds a bit more formal or literary

Spanish often prefers a phrase like con + noun where English might use an adverb.

Yes, it is normal and correct here.

When a subordinate clause introduced by aunque comes first, Spanish usually separates it with a comma:

• Aunque no siempre estoy de acuerdo, intento...

That comma helps mark the end of the opening concessive clause and the start of the main clause.

Yes, you could, but the nuance changes slightly.

• Aunque no siempre estoy de acuerdo presents the disagreement as a real fact
• Aunque no siempre esté de acuerdo sounds a bit more concessive, abstract, or less directly asserted

In many contexts both are possible, but the indicative version in your sentence is very straightforward and natural.

Yes. It sounds natural, clear, and educated.

Several features fit Spain-Spanish well:

• enfadarme is very common in Spain
• debatir and argumentar sound thoughtful and precise
• con calma is very natural everyday Spanish

So this is a good model sentence for expressing calm disagreement politely.