The answer to your question depends on many issues. Does your boyfriend have a work permit through TPS? Are you eligible to become a US citizen? That might help. You two should consult an immigration attorney because he may be able to apply here, or might have to return to El Salvador.
If your son-in-;aw and daughter were married for less than 2 years when she petitioned for him, he has a conditional residency. If he did not file the I-751 to remove the conditions two years after getting his conditional green card he may be at risk of loosing his residency. US Citizenship and Immigration Services can accept late filings, but he would have to have a reason. If his I-751 is not approved he will loose his residency. He may have to file this in front of the Immigration Judge....
Your husband should have been provided with a criminal defense attorney to represent his interests in the criminal case. You can speak with that attorney and he can help you find out if ICE is interested in your husband. In some cases your husband can be paroled into the U.S. while the criminal case proceeds for which the government wants to use him as a witness. Many times you must pay a bond for the release.
I have had an I-130 petition approved where the petitioning spouse was under the age of 18. She was 17 and in Oregon she was able to marry. You can definitely file a petition for your spouse at age 20.
While the co-sponsor may not be liable to pay your mother's Macy's account, he may be on the hook if your mother receives a mean tested benefit, ie. food stamps, HUD rental assistance. If you decide to wait until you make enough money your application may be denied and you have to pay all the filing fees. Perhaps you have assets that can cover your shortfall?
If the priority date is current and there is a visa available now you should apply now. If you wait the priority date can retrogress. Also, I do not know from your question whether you have an dependents who are under 21. In some cases only children who file within one year of their priority date becoming current can benefit from the Child Status Protection Act, which freezes the child's age so they do not age out and slip into a visa preference category that has a long backlog.
You should provide more details like your immigration status when you left in 2007 and who arrested you upon your return in 2011. If you were a legal permanent resident and you left the USA for more than 6 months, you may have been paroled into the country and then issued a notice to appear in Immigration Court. please provide a few more details.
Once the I-485 is filed the applicant does not continue to accrue unlawful presence. So even if his I-485 is denied, he would still have about 3 months until he started to accrue unlawful presence. I would not be worried at this point.