Current processing times is more like 8 monthsSee question
Unfortunately, once your brother married his Preference Category does change. He will no longer be current, so he will not be able to come to the U.S. ahead of his wife. You may wish to explore other options on his behalf. Perhaps he might qualify for a non-immigrant visa in the meantime?See question
You may travel with the I-551 stamp in your passport. Will you be able to return before the expiration? As previous attorney mentioned, it can take a few months before receiving the Green Card in the mail. Did you pay the fee at the Consulate or once you entered the U.S.?See question
Yes, you may send in a written request asking for a reschedule of the interview appointment. In fact, that is the only way you should do it. However, the bigger question is will your spouse be eligible for Naturalization after such a prolonged stay outside the U.S.? How are they going to meet the physical presence requirement?
Must have resided continuously within the U.S. from the date the application filed up to the time of admission to citizenship
Must be physically present in the U.S. for at least one-half of the 5 years (or one-half of 3 years if the applicant is the spouse of a USC).
Applying for a tourist visa would not negatively impact your I-130 filing. But the chances of being granted a visitor visa are pretty slim, especially in light of the fact that you have already been turned down previously. It is unfortunate, because you may have a legitimate intention of just coming to visit while you are waiting for your priority date to become current.
What was the validity date of your previous H-1B and I-94 prior to joining 2nd employer? If new employment,extension of stay was granted during previous application, why is there a concern now?See question
You will want to order the necessary forms to have on hand. It is highly unlikely USCIS would deny your petition solely based on incomplete tax returns. As long has you have provided other evidence to prove the bon fides of the relationship, it is likely USCIS will either issue an RFE requesting the signed forms, or if an interview is scheduled, they will request them at that time. Please note the new I-751 processing time is over 18 months, so there will be another tax filing before your case is adjudicated.See question
Yes, the previous marriage must be disclosed, and the final divorce decree must be provided to USCIS when you file.
Good luck to you both!See question
With a case as complex as yours, you definitely need to consult an immigration attorney. Waiver filing is very complex and requires a great deal of documentation. Also, beyond that, you would not be filing the I-485, and certainly not outside the U.S. Please schedule a consultation appointment with an experienced immigration attorney in your area.See question
You are indeed employment authorized. Your Conditional Green Card and I-751 receipt notice should be sufficient. The only other option is to make an infopass appointment at the local USCIS office and request an I-551 stamp in your passport.
Good luck to you.See question