It depends. Generally, it takes 90 days from the time of filing. However, there are some types of applications where the work card will only be approved if the underlying case is approved - such as Deferred Action for Childhood Arrivals or U status.
A copy of your I-589 receipt should be sufficient. In regards to your current status, you could put a myriad of things such as: "overstay" or "expired OPT." Truly, though, if you're struggling with putting together your application, you may want to hire an immigration attorney to make sure everything gets done correctly.
You can, if you're eligible. You can file 4 years 9 month after obtaining LPR status - but if you obtained your LPR status through a marriage (and you are still married to the same person), you need only wait 2 years and 9 months. In all likelihood you won't have your application processed before your green card expires, though.
I completely understand your frustration, but there's really no good explanation for why some are approved before you. It could simply be a particular officer's caseload. There are still over 120,000 cases waiting for a final review and your file could very well be in there. I would continue to check your case online at www.uscis.gov. Since DACA is so new, there's no way to tell what "average processing times are," but if it's been more than six months, I would talk with an attorney about...
Yes, you will need to do a new I-864 with your new spouse. As the other attorney mentions, you may want to speak with another attorney to make sure everything is in order for your new green card application.
Well, there are a few options and you'll probably want to talk to a family law attorney, since marriage laws vary from state to state. In some places, as long as the marriage to the other wife is now terminated, you marriage would be considered automatically valid from the date that it happened. In some other places, you'll need to get remarried to your husband.
You won't need to disclose anything to USCIS until it comes time to remove the conditions on your green card - and you'll certainly...
I have never seen a situation where the co-sponsors payment issues were a concern for USCIS as a joint-sponsor. The IRS and USCIS don't talk to each other, so as long as your joint sponsor meets the requirements listed on the I-864, it should be okay.