Can my sister (she is an american citizen) file I-864 for me in the case my american husband doesn't want to file it?

In my humble opinion because of your husband's actions you do not meet the definition of a good faith commingled marriage and therefore the I864 is...

Travel outside US but greencard havent been received yet

Make an Infopass appointment and get his passport stamped.

Is it possible for me and my family to get a Green Card without having to be sponsored by the employer?

Absent the employer, you will need either a family member, the lottery, or a size able investment to get a green card.

You can apply with the EAD card and your birth certificate at any social security office.

Must I include sworn affidavits as evidence in my application to remove conditions on my green card?

You should provide as much evidence as you have available. Marriage fraud is high on immigration's radar.

Its much better if my wife file the n 400 form for me ? or its better if i do it to my self ?

The N-400 is yours including the tests. No reason your wife cannot help you with the form.

Can I get divorce and child custody? Can I defend myself about hiding for the last 12 months with the fact that I was scared.

Divorce is family law forum work. I have changed the section to family so that they may respond.

What can i do to win my case what are my options ?

You do not provide enough info. What drugs, single or multiple instances, misdemeanor or felony, possession or distribution, etc. Best to visit...

Does it make sense to file I-485 (Adjustment of status) along with the orig. application for family based GC through BROTHER ?

That is not permitted and it will be returned. Depending how you file and pay, the whole package may be returned.

Do I need to know my future itineraries to and from Europe at the time of application to get a "multiple entry" Schengen Visa?

You will need a copy of your return ticket when you apply for the multiple entry visa.