Is it legal for the employer to deny to hire me when I am on F1-OPT and waiting for green card?

I think there may be some lack of clarity about the question. It sounds like you have work authorization through September on your OPT. In...

What consequences can a illegal immigrant with a clean record have after being charge with patronizing a prostitute?

A single incident of patronizing a prostitute doesn't make you inadmissible if you were applying for permanent residence, but, as others have said,...

Getting a I-797C or receipt time frame.

If you filed the I-601 on your own or with the assistance of someone who is not an actual licensed attorney with years of experience specifically...

Applying I-485 without including the spouse?

I agree you could probably adjust provided you are still married at the time. If there is a divorce, then you will not be able to do so.

Form I-129F: How to answer Part A Question 11: "Have you ever filed for this or any other alien fiancé or husband/wife before?"

Yes

Dual citizenship

There are a number of requirements we need to analyze including when/how you came to US. I'd be happy to go through it with you. Some of what we...

U.S citizen petitioning for sibling.

Sadly, no. I'd be happy to explain more, but that's the straightforward answer

I-130 Petition and G-325A Form

Even though there is a process ahead of you, ultimately the purpose is for permanent residence, and that's the answe I'd suggest

Technically, yes, but I always tell clients to sign with blue ink, because USCIS on occasion will reject a form with a black signature saying it is...

I have some immigration questions actually family related questions

He needs to have a personal meeting with a lawyer. These situations depend very much on the unique facts and history of the couple. There could be...