Der Fluchtweg ist für den Brandschutz wichtig.

Because Fluchtweg is a masculine noun in German, so in the nominative singular it takes der.

In this sentence, der Fluchtweg is the subject, and subjects are typically in the nominative case:

• der Fluchtweg = nominative masculine
• den Fluchtweg = accusative masculine
• dem Fluchtweg = dative masculine

So der is used here because Fluchtweg is both masculine and the subject of the sentence.

A very helpful clue is that Fluchtweg is a compound noun:

• Flucht = escape / fleeing
• Weg = way / path / route

In German, the last part of a compound noun determines the gender.
Since Weg is masculine (der Weg), the whole compound is also masculine:

• der Weg
• der Fluchtweg

This is a very useful rule for long German nouns.

Because German main clauses usually follow the verb-second rule (V2). That means the finite verb comes in the second position.

Here the first element is:

• Der Fluchtweg

So the verb comes next:

• Der Fluchtweg ist ...

That is standard German word order for a simple statement.

Because the preposition für always takes the accusative case.

So after für, you need the accusative form of the article:

• masculine nominative: der Brandschutz
• masculine accusative: den Brandschutz

That gives:

• für den Brandschutz

This is an important rule to memorize:

• für + accusative

Yes. The noun is der Brandschutz.

It is also a compound noun:

• Brand = fire
• Schutz = protection

The final part is Schutz, and der Schutz is masculine, so the whole compound is masculine too:

• der Schutz
• der Brandschutz

Because wichtig is being used as a predicate adjective after sein.

In German:

• adjectives before a noun usually take endings
  
  • ein wichtiger Fluchtweg
• adjectives after verbs like sein, werden, or bleiben do not take endings
  
  • Der Fluchtweg ist wichtig.

So in your sentence, wichtig stays unchanged because it comes after ist.

It is a prepositional phrase that shows for what purpose / in relation to what the escape route is important.

The structure is:

• Der Fluchtweg = subject
• ist = verb
• für den Brandschutz = prepositional phrase
• wichtig = predicate adjective

So the sentence is saying that the escape route is important for fire safety / with regard to fire protection.

Yes. German often allows different word orders for emphasis, as long as the finite verb stays in second position.

For example:

• Der Fluchtweg ist für den Brandschutz wichtig.
• Für den Brandschutz ist der Fluchtweg wichtig.

Both are grammatical. The second version emphasizes für den Brandschutz more strongly.

Because in German, all nouns are capitalized.

In this sentence, the nouns are:

• Fluchtweg
• Brandschutz

Words like ist, für, and wichtig are not nouns, so they are not capitalized.

This is a basic spelling rule in German and helps you identify nouns quickly.

Not exactly.

• der Fluchtweg = escape route / evacuation route
  This is the path or route people use to get out safely.
• der Notausgang = emergency exit
  This is the actual exit door or exit point.

So a Fluchtweg may lead to a Notausgang.

Yes, absolutely. That word order is also natural.

Compare:

• Der Fluchtweg ist für den Brandschutz wichtig.
• Der Fluchtweg ist wichtig für den Brandschutz.

Both are correct. The difference is mainly one of rhythm and emphasis.

The version with wichtig at the end sounds slightly more focused on the final idea of importance, while the original version puts the prepositional phrase before wichtig.

A few pronunciation points may help:

• Fluchtweg
  The ch in Flucht is pronounced like the German ach-Laut, a rough sound made in the back of the mouth.
• Brandschutz
  The sch sounds like English sh.
  The tz at the end sounds like ts.

Very roughly for an English speaker:

• Fluchtweg ≈ FLOOKHT-vayk or FLOOKHT-vayg depending on accent
• Brandschutz ≈ BRAHNTS-shoots

These rough spellings are only approximations, but they can help at first.