החדשות האלה הפתיעו אותי יותר ממה שציפיתי.

Because in Hebrew, חדשות is a plural noun grammatically. So it takes:

• a plural demonstrative: האלה
• a plural verb: הפתיעו

So Hebrew says something closer to these news surprised me, even though that sounds ungrammatical in English. This is just one of those places where Hebrew and English organize the idea differently.

Both are possible, but they mean slightly different things structurally.

• החדשות האלה = this news / these news items
• אלה החדשות = these are the news or this is the news

In your sentence, החדשות האלה is a noun phrase inside a larger sentence, so it means this news / these pieces of news.

Also, in Hebrew, when a demonstrative like this/these comes after the noun, the normal colloquial pattern is:

• הספר הזה = this book
• הילדה הזאת = this girl
• החדשות האלה = this news / these news items

This is the normal Hebrew pattern with post-noun demonstratives.

When you say this/that/these/those after a noun, Hebrew usually uses:

• ה... הזה
• ה... הזאת
• ה... האלה

So:

• ספר = a book
• הספר הזה = this book

It may look like double definiteness from an English point of view, but in Hebrew this is just the standard construction.

הפתיעו is the past tense, 3rd person plural form of להפתיע = to surprise.

So literally it means:

• they surprised

In this sentence, the subject is החדשות האלה, which is grammatically plural, so the verb is plural too:

• החדשות האלה הפתיעו אותי
• This news surprised me

Even though English uses singular news, Hebrew uses the plural verb because חדשות is plural.

Because אותי means me, while אני means I.

Here, me is the direct object of the verb surprised:

• אני = I
• אותי = me

So:

• הפתיעו אותי = surprised me

Hebrew often uses special object forms with את built into them:

• אותי = me
• אותך = you
• אותו = him
• אותה = her
• אותנו = us

Very literally, it is something like:

• יותר = more
• ממה = than what / from what
• שציפיתי = that I expected

So the whole phrase means:

• more than what I expected
• more naturally in English: more than I expected

This is a very common Hebrew pattern.

For example:

• זה היה קשה יותר ממה שחשבתי = It was harder than I thought
• הוא הגיע מוקדם יותר ממה שציפיתי = He arrived earlier than I expected

Because when than is followed by a whole clause, Hebrew often uses ממה ש....

Compare:

• יותר טוב ממני = better than me
• יותר טוב ממה שחשבתי = better than I thought

So:

• before a noun or pronoun: often just מ־
• before a clause: often ממה ש־

In your sentence, what follows is really a clause:

• שציפיתי = that I expected

So יותר ממה שציפיתי is the natural structure.

Yes, it can.

• יותר ממה שציפיתי = more than I expected
• יותר משציפיתי = more than I expected

Both are used.
ממה שציפיתי sounds a bit fuller and more explicit.
משציפיתי is a bit more compressed.

In everyday Hebrew, both are understandable and common.

Because the object is understood from the context.

This works the same way in English:

• It surprised me more than I expected

You do not have to say:

• more than I expected it would surprise me

Hebrew is doing the same kind of shortening. The fuller idea would be something like:

• יותר ממה שציפיתי [שהחדשות האלה יפתיעו אותי]
• more than I expected [that this news would surprise me]

Since that extra part is obvious, Hebrew leaves it out.

ציפיתי is the 1st person singular past tense of לצפות in the sense of to expect.

The ending ־תי often marks I in the past tense:

• חשבתי = I thought
• ידעתי = I knew
• ציפיתי = I expected

So:

• שציפיתי = that I expected

Yes. The sentence is very natural.

It goes like this:

• החדשות האלה = the subject
• הפתיעו אותי = surprised me
• יותר ממה שציפיתי = more than I expected

So the structure is basically:

Subject + Verb + Object + Comparison

This is a very normal Hebrew word order for a sentence like this.

In standard Hebrew, חדשות is normally treated as a plural noun grammatically, especially in expressions like this one.

That is why you see:

• החדשות האלה
• החדשות היו מפתיעות
• החדשות הפתיעו אותי

Even when the meaning in English is the mass noun news, Hebrew still commonly keeps the plural grammar.