ההצעה הזאת ראויה לדיון.

Because the noun itself is הצעה and already begins with the letter ה. When you add the definite article ה־ meaning the, you get:

• הצעה = proposal
• ההצעה = the proposal

So the spelling naturally ends up with two ה letters in a row. In pronunciation, you normally hear this as ha-hatsa'ah.

In Hebrew, demonstratives like this and that usually come after the noun:

• ההצעה הזאת = this proposal
• literally: the proposal this

That is the normal Hebrew word order. English puts this before the noun, but Hebrew usually puts זאת / זה / אלה after it.

That is just how standard Hebrew works with a noun plus a demonstrative.

Hebrew says:

• ההצעה הזאת = this proposal

not usually:

• הצעה הזאת

The noun takes the definite article ה־, and the demonstrative also appears in its definite form. So Hebrew effectively marks definiteness twice in this structure.

Because הצעה is a feminine singular noun, and the demonstrative has to agree with it.

• masculine singular: זה
• feminine singular: זאת
• masculine/feminine plural: אלה

So:

• הספר הזה = this book
• ההצעה הזאת = this proposal

Because ראוי also has to agree with the noun it describes.

Since הצעה is feminine singular, the adjective appears in the feminine singular form:

• masculine singular: ראוי
• feminine singular: ראויה
• masculine plural: ראויים
• feminine plural: ראויות

So:

• הספר ראוי לקריאה = the book is worthy of reading
• ההצעה ראויה לדיון = the proposal is worthy of discussion

It is made of:

• ל־ = to, for
• דיון = discussion

So לדיון literally means for discussion or to discussion, but in this sentence the natural English meaning is worthy of discussion.

The pattern is:

• ראוי ל־... = worthy of ..., deserving ...

So ראויה לדיון means worthy of discussion.

Because in Hebrew, the verb to be is usually omitted in the present tense.

So Hebrew says:

• ההצעה הזאת ראויה לדיון

where English says:

• This proposal is worthy of discussion

This is completely normal. In past or future tense, Hebrew does use forms of to be when needed.

It is correct and natural, but it sounds a bit formal or elevated. It means something like:

• worthy of discussion
• deserves discussion
• merits discussion

In more everyday speech, someone might also say something like:

• צריך לדון בהצעה הזאת = we need to discuss this proposal
• כדאי לדון בהצעה הזאת = it is כדאי / worth discussing this proposal

So ראויה לדיון is perfectly good Hebrew, just somewhat more formal in tone.

Yes. Both are common, but there is a small register difference:

• ההצעה הזאת = this proposal
• ההצעה הזו = this proposal

In modern spoken Hebrew, הזו is very common.
הזאת is also very common and completely standard.
Learners should understand both.

You may also see the more formal written style:

• הצעה זו = this proposal

That version is especially common in formal writing.

Yes, but the given order is the most neutral and natural:

• ההצעה הזאת ראויה לדיון

Hebrew can sometimes move things around for emphasis, but for a simple statement, this is the standard order:

• noun phrase first: ההצעה הזאת
• description after it: ראויה לדיון

So if you are learning basic sentence structure, this is a very good model to follow.

A simple pronunciation guide is:

ha-hatsa'ah ha-zot re'uyah le-diyun

A few helpful notes:

• ההצעה sounds like ha-hatsa'AH
• הזאת sounds like ha-ZOT
• ראויה sounds like re'u-YAH
• לדיון sounds like le-di-YUN

The main stress is typically near the end of each word:

• hatsa'AH
• haZOT
• re'uYAH
• diYUN

Because את is only used before a definite direct object, and this sentence does not have a direct object.

This is not an action sentence like:

• ראיתי את ההצעה = I saw the proposal

Instead, it is a description sentence:

• ההצעה הזאת ראויה לדיון = this proposal is worthy of discussion

So את is not needed here.