Для меня сейчас важнее всего спокойствие.

Меня is the genitive singular form of я.

It appears in the phrase для меня, because the preposition для requires the genitive case.

So:

• я = I
• меня = me / of me
• для меня = for me

In this sentence, для меня means something like for me, to me personally, or from my point of view.

Для меня adds the idea of as far as I am concerned or for me personally.

So Для меня сейчас важнее всего спокойствие feels like:

• For me, right now, calm is the most important thing
• As for me, what matters most now is calm

Using мне is possible in many similar structures, but для меня often sounds a bit more explicit or contrastive, as if you are highlighting a personal perspective.

Compare:

• Мне важно спокойствие = Calm is important to me.
• Для меня важнее всего спокойствие = For me, calm is the most important thing.

In Russian, the verb to be is usually omitted in the present tense.

So where English says:

• Calm is the most important thing

Russian often simply says:

• Спокойствие важнее всего

There is no present-tense есть here. That is completely normal.

Важнее is the comparative form of важный (important).

So:

• важный = important
• важнее = more important

In Russian, comparative forms like важнее, лучше, больше, сильнее do not change for gender, number, or case the way ordinary adjectives do.

Here, важнее means more important, but together with всего it gives the meaning most important of all.

This is a very common Russian pattern:

• важнее всего = most important of all / more important than anything else

Here всего is the genitive singular/neuter form related to всё (everything).

Literally, the idea is something like:

• more important than everything

But in natural English, you usually translate it as:

• the most important thing
• most important of all
• above all

So важнее всего is functioning like a superlative meaning, even though grammatically it is built from a comparative form.

Semantically, yes; grammatically, not exactly.

Russian often expresses the most ... in two main ways:

• with a true superlative-like form: самый важный
• with a comparative + всего: важнее всего

So:

• самый важный = the most important
• важнее всего = more important than everything else / most important of all

In this sentence, важнее всего is very natural and idiomatic.

Спокойствие is in the nominative singular because it is the thing being identified as the most important.

It is the noun that answers the question:

• What is most important for me right now?
• Спокойствие.

So grammatically, it is the main noun of the statement.

Also, спокойствие is a neuter noun, which is why its dictionary form ends in -ие.

Спокойствие means calm, peace, peace of mind, tranquility, or calmness, depending on context.

It can refer to:

• emotional calm
• absence of stress
• a peaceful state
• quiet stability

In this sentence, it most likely means peace of mind or calmness in a general emotional sense.

Russian word order is flexible, and word order often shows topic and focus, not just grammar.

This order does a few things:

• Для меня sets the personal point of view first
• сейчас adds the time frame: right now
• важнее всего gives the evaluation
• спокойствие comes at the end, which gives it strong focus

So the sentence builds toward the key idea:

• For me, right now, the most important thing is calm.

Ending with спокойствие makes that word sound especially important.

Yes. Russian allows several natural variants, but the emphasis changes.

For example:

• Сейчас для меня важнее всего спокойствие.
  Slightly more emphasis on right now.

• Спокойствие сейчас для меня важнее всего.
  More emphasis on calm from the start.

• Для меня спокойствие сейчас важнее всего.
  Very close in meaning, with a slightly different rhythm.

All of these are understandable and natural. The original version is smooth and expressive.

It is mostly neutral to slightly reflective.

It sounds natural in:

• conversation
• interviews
• personal statements
• writing

It can feel a little thoughtful or introspective, especially because of важнее всего and спокойствие. It is not slangy, and it is not overly formal either.