Learn Hardcore German: Zu viel Vorrang für Arbeit ohne Erholung macht auf Dauer krank. - Too much priority for work without recovery makes you ill in the long run.

You don’t need es here because German can use a whole phrase as the subject. This is like English Too much priority for work without rest makes you ill in the long run: the subject is the whole Too much priority for work without rest, not it.

Why is it macht and not machen?

The verb agrees with the head noun of the subject, which is Vorrang (singular, masculine):

der Vorrang → macht
If the subject were plural, you’d get machen (e.g. Viele Dinge machen auf Dauer krank).

Even though the subject phrase is long, Vorrang is singular, so you must use macht.

What exactly does Vorrang mean here, and why not just say zu viel Arbeit?

Vorrang means priority, precedence, or being put first.

zu viel Arbeit = too much work (quantity of work)
zu viel Vorrang für Arbeit = work is given too high a priority (it comes before other things, like rest or family)

So the sentence is not about working too many hours as such, but about the one-sided value system where work is always put first and rest is neglected.

You often see patterns like:

etwas hat Vorrang (vor + Dativ) – X takes precedence over Y
jemandem / etwas Vorrang geben – give priority to X

Here, that idea is condensed into the noun phrase zu viel Vorrang für Arbeit.

Why is there no article before Vorrang? Why not zu viel der Vorrang?

When zu viel (too much) is used as a quantity expression before an abstract noun, German usually omits the article:

zu viel Vorrang – too much priority
viel Respekt, wenig Zeit, zu viel Stress

You would only use an article with Vorrang if you were talking about a specific or previously mentioned priority, for example:

Der Vorrang der Arbeit macht auf Dauer krank.
(The priority given to work makes you ill in the long run.)

But that sounds more formal and heavier. Zu viel Vorrang für Arbeit is more natural and general.

Why is it für Arbeit and not something like der Arbeit or vor Arbeit?

für here marks what is being given the priority:

Vorrang für Arbeit = priority for work / priority given to work.

Other common patterns with Vorrang:

Vorrang haben vor + Dativ:
Die Familie hat Vorrang vor der Arbeit. – The family has priority over work.
jemandem / etwas Vorrang geben:
Wir geben der Gesundheit Vorrang. – We give priority to health.

So you could also phrase your sentence as:

Wenn man der Arbeit zu viel Vorrang gibt, macht das auf Dauer krank.

Here der Arbeit is dative because of the verb phrase jemandem / etwas Vorrang geben. In the original sentence, using the simple noun phrase Vorrang für Arbeit is more compact.

What is ohne Erholung doing grammatically? Does it belong to Arbeit?

Yes, ohne Erholung most naturally belongs to Arbeit:

Arbeit ohne Erholung = work without rest / recovery.

So inside the subject you have:

Vorrang [für Arbeit [ohne Erholung]]

ohne is a preposition that takes the accusative. Here you don’t see the case ending because Erholung is singular and has no article, and its nominative and accusative forms look the same.

You could expand it:

für Arbeit ohne ausreichende Erholung – for work without sufficient rest
für die Arbeit ohne jede Erholung – for (the) work without any rest

Why are Arbeit and Erholung used without articles?

Both Arbeit and Erholung are abstract, mass-like nouns here, and German often omits articles with this kind of general concept:

Arbeit ist wichtig. – Work is important.
Erholung ist notwendig. – Rest is necessary.
Zu viel Stress ohne Erholung ist ungesund.

If you make them more specific, you can add an article:

Die Arbeit ohne Erholung im letzten Jahr hat ihn krank gemacht.
(That specific work without rest last year made him sick.)

In the original sentence, they are meant in a general sense, so no article is more idiomatic.

Is macht … krank a fixed expression? How does this grammar work?

It’s a very common pattern: machen + (object) + adjective.

Here:

macht = verb
(Menschen / einen / dich) = understood object, not expressed
krank = predicate adjective describing that object

The full underlying idea is:

Zu viel Vorrang für Arbeit ohne Erholung macht (Menschen) auf Dauer krank.
Stress macht dich krank.
Das macht mich wahnsinnig.

So krank is not an adverb, but an adjective that says what the (implicit) object becomes.

You could also say:

Davon wird man auf Dauer krank. – One gets ill from that in the long run.

But X macht krank is a very natural and short way to say X makes you ill / is harmful to your health.

What does auf Dauer mean exactly, and is it idiomatic?

auf Dauer is a fixed expression meaning in the long run, over time, in the long term.

Literally, it’s something like “on duration”, but you should treat it as an idiom:

Das hält man auf Dauer nicht aus. – You can’t endure that in the long run.
Auf Dauer ist das keine Lösung. – That’s no long-term solution.

In the sentence, auf Dauer modifies krank machen:

macht auf Dauer krank = makes you ill if it goes on for a long time.

So it doesn’t mean immediately, but gradually over a longer period.

Can I move auf Dauer to a different position, like macht krank auf Dauer?

Grammatically, several positions are possible, but they differ in naturalness and emphasis:

Zu viel Vorrang für Arbeit ohne Erholung macht auf Dauer krank.
– This is the most idiomatic and neutral.
Zu viel Vorrang für Arbeit ohne Erholung macht krank auf Dauer.
– Understandable, but less natural; auf Dauer normally comes before the adjective in this pattern.
Auf Dauer macht zu viel Vorrang für Arbeit ohne Erholung krank.
– Also fine; now auf Dauer is emphasized by being in the first position: In the long run, X makes you ill.

German prefers to place short adverbials like auf Dauer before the predicate adjective (krank) in machen + Adj constructions.

Could you rewrite the sentence in simpler or more explicit German?

A few natural rephrasings:

Wenn man der Arbeit zu viel Vorrang gibt und sich nicht erholt, wird man auf Dauer krank.
(Uses wenn
- man
  - wird krank.)
Wer immer nur arbeitet und sich nicht erholt, wird auf Dauer krank.
Zu viel Arbeit und zu wenig Erholung machen den Menschen auf Dauer krank.
Wenn die Arbeit immer wichtiger ist als Erholung, macht das auf Dauer krank.

All of these preserve the meaning but use slightly more explicit structures, which may be easier for learners to parse.