Îmi place ordinea din bucătărie când totul este la locul lui.

Because Romanian uses a plăcea a bit like English to please.

So:

• Îmi place ordinea literally means The order pleases me
• îmi = to me
• place = pleases / is pleasing

This is the normal way to say I like in Romanian.

A few quick comparisons:

• Îmi place cartea. = I like the book.
• Îmi plac cărțile. = I like the books.

So the thing you like is grammatically the subject of a plăcea.

Because ordinea is singular.

With a plăcea, the verb agrees with the thing being liked:

• Îmi place ordinea. = I like the order/tidiness.
  
  • ordinea = singular, so place
• Îmi plac farfuriile. = I like the plates.
  
  • farfuriile = plural, so plac

This is one of the most important patterns to notice with a plăcea.

Îmi is the unstressed dative pronoun meaning to me.

So:

• îmi = to me
• îți = to you
• îi = to him/her
• ne / nouă ne = to us, etc.

In this sentence, îmi place means it is pleasing to me.

You may also see the stressed form mie:

• Mie îmi place ordinea.

That also means I like order/tidiness, but mie adds emphasis, like me, I like...

Because ordinea is the definite form: the order / the tidiness.

Romanian usually puts the definite article at the end of the noun:

• ordine = order, tidiness (indefinite/general)
• ordinea = the order, the tidiness

So:

• Îmi place ordine. would be wrong here
• Îmi place ordinea. is correct

In this sentence, the speaker is talking about a specific kind of order: the order/tidiness in the kitchen.

This is a very common learner question.

In Romanian, when a noun is being described by its location, din often corresponds to English in:

• masa din bucătărie = the table in the kitchen
• lumina din cameră = the light in the room
• ordinea din bucătărie = the order/tidiness in the kitchen

Here, din bucătărie modifies the noun ordinea.

By contrast, în bucătărie is more natural when it goes with the whole situation or with a verb:

• Este ordine în bucătărie. = There is order in the kitchen.
• Gătesc în bucătărie. = I cook in the kitchen.

So in this sentence, din bucătărie is the natural choice because it is attached to ordinea.

Când means when and introduces a subordinate clause:

• când totul este la locul lui = when everything is in its place

So the full sentence has two parts:

• Îmi place ordinea din bucătărie
• când totul este la locul lui

Together, the second part tells you under what condition / in what situation the speaker likes the kitchen’s order.

Totul means everything.

Even though everything refers to many things in meaning, it is grammatically singular, just like in English:

• Everything is ready
• Totul este gata

That is why the verb is singular:

• totul este, not totul sunt

So:

• totul = everything
• este = is

Yes. Este and e both mean is.

• totul este la locul lui = more full/neutral
• totul e la locul lui = more common in everyday speech

Both are correct. In writing, este can sound slightly more careful or formal, but e is extremely normal.

La locul lui is a very common Romanian expression meaning:

• in its place
• where it belongs
• in the proper place

Literally, it is something like at its place, but in natural English we usually say in its place.

So:

• totul este la locul lui = everything is in its place

This is an idiomatic phrase, and learners should remember it as a chunk.

Because the meanings are different.

• la locul lui = in its proper place
• în locul lui = in its place / instead of it-him

Compare:

• Farfuria este la locul ei. = The plate is in its proper place.
• Am pus paharul în locul farfuriei. = I put the glass in place of the plate.

So in your sentence, la locul lui is the correct idiom for order and tidiness.

Here, lui means its in the expression la locul lui.

Romanian uses lui for masculine/neuter singular possession. Since totul is grammatically singular, lui fits naturally.

But in practice, this whole phrase is best learned as a set expression:

• la locul lui / ei = in its proper place

Examples:

• Cuțitul este la locul lui. = The knife is in its place.
• Cartea este la locul ei. = The book is in its place.

So in the sentence, totul este la locul lui means everything is where it belongs.

Yes, Romanian word order is fairly flexible, but the original version is the most neutral:

• Îmi place ordinea din bucătărie când totul este la locul lui.

You could also say:

• Când totul este la locul lui, îmi place ordinea din bucătărie.

That puts more focus on the when everything is in its place part.

You could even say:

• Ordinea din bucătărie îmi place când totul este la locul lui.

But that sounds more marked or contrastive, as if you are emphasizing the order in the kitchen specifically.

So the original sentence is a very natural, standard way to say it.