How long does it take to get N-400 application placed in line for interview?

The executive order temporarily suspends processign for a 90 day period. However, the delay may be extended.

If eligible as a step daughter chose the option that applies for stepdaughter of a US citizen.

When should I apply for COS?

File within 6 months of start of classes. You may take classes as an H-4 which the change is pending.

What should I do? I am really worried.

That is the standard procedure for USCIS.

From your description it appears that you have been determined to entered into a sham marriage (INA 204(c)).You need to have this determination...

Hello, I am on F-1 Opt and planning on applying for non profit H-1 B for a job that is at Nashville Tennessee area.

The employer must pay the prevailing wage for the position, among other requirements..

Fix my wife recidency?

There are a few exceptions to departing such as parole in place or travel on advance parole. Talk directly with an immigration attorney

Can my life long friends who are regarded as family sponsor my wife and I to live in America

You will need either an employer or family member to petition for you or obtain status based on investment. Contact an immigration attorney...

Will 1099 on your tax filing affect the decision on I-485 (and RFE also)?

Talk with the employer's immigration attorney preparing the application.

I want to apply for citizenship, but am also planning on going out of the country in april. If I apply will that delay it?

travel while the application is pending is not an issue unless you have so much travel you do not meet the residence or physical presence...