من هنوز خبر ندارم، اما منتظر او هستم.

Yes. In Persian, subject pronouns are often omitted because the verb ending already shows the person.

• ندارم = I do not have
• هستم = I am

So هنوز خبر ندارم، اما منتظر او هستم is already clear without من. Keeping من adds a bit of emphasis, contrast, or explicitness.

هنوز means still or yet.

In a negative clause like هنوز خبر ندارم, it often matches English yet:

• I don't have any news yet
• I still don't know

Its position before the predicate is very normal.

Because خبر داشتن is a common expression meaning to have news / to be informed / to know about something.

So:

• نمی‌دانم = I don't know
• خبر ندارم = I have no news / I haven't heard / I'm not informed

They can overlap in translation, but خبر ندارم suggests a lack of information or updates, not just general ignorance.

Because the expression uses the verb داشتن (to have), not بودن (to be).

The pattern is:

• خبر دارم = I have news / I know
• خبر ندارم = I don't have news / I don't know

So نیستم would not fit this expression.

Because منتظر is not a full verb by itself here. It works like an adjective meaning waiting or expectant, so Persian uses it with a form of بودن (to be):

• منتظر هستم = I am waiting

So منتظر او هستم literally means I am waiting for him/her.

Yes. In pronunciation, there is normally an ezafe link:

• منتظرِ او
• pronounced roughly montazer-e u

In ordinary Persian writing, that -e sound is usually not written, so you just see منتظر او.

Because او is not being treated like the direct object of a regular transitive verb here. It is the complement of منتظر.

So Persian says:

• منتظر او هستم = I am waiting for him/her

not:

• منتظر او را هستم ✘

It is correct, but it sounds a bit formal or written. In everyday spoken Persian, people often say:

• اون instead of او
• or use the attached pronoun -ش

So more conversational versions would be:

• هنوز خبر ندارم، ولی منتظر اون هستم
• هنوز خبر ندارم، ولی منتظرش هستم
• هنوز خبر ندارم، ولی منتظرشم

Also, spoken Persian often prefers ولی over اما.

Yes. خبری ندارم is also very common and often sounds very natural for I have no news / I haven't heard anything.

So both are possible:

• خبر ندارم
• خبری ندارم

The version with -ی is especially common when you mean any news in a general sense.

A careful pronunciation is:

man hanooz khabar nadāram, ammā montazer-e u hastam

A more natural spoken version might sound closer to:

hanooz khabari nadāram, vali montazeresh hastam

depending on style and context.