If your attorney submitted a G-28 and checked the box to have your security/identity documents (such as an EAD or resident card) sent to the attorney, it should go there.
Is he already out of status? And if yes, was he out of status more than 180 days before filing for adjustment of status? Although filing for adjustment of status stops the accrual of any unlawful presence, it does not give anyone "legal status."
You do not even need to include a copy of your passport with the N-400 application. Bring the copy of old passport and the new one that's issued to you to the interview and explain what happened to the old one.
I do not believe the errors you mention are detrimental to your application as they seem fairly minor. Still, you should send USCIS a letter with the corrections (along with a copy of your receipt).
A certified final divorce decree should be sufficient. Anything that is not in English must be translated into English before submitting to USCIS.
It appears you may be subject to the 3-year bar. Did you already obtain a waiver of your unlawful presence? Do you have proof that USCIS said you "wait for your documents in US territory?" You should definitely consult with an attorney before leaving the US.
Agree with other attorney that you can't "maintain" H-1B status if you're outside of the US and working abroad, but after the 1.5 years, the US company can petition you for the H-1B again and you wouldn't be counted toward the cap since you already obtained one. And if you performed managerial duties while working for the foreign entity for at least a year, the US entity could even petition you for L-1A visa which may be better if you're considering EB1C.
You should consider it. An experienced attorney can properly prepare you for the interview, prepare supplemental documents that can be helpful to your case, and attend the interview with you.
You don't provide enough information to answer your question, as you did not state the basis of the 10-year bar. But the bar is a complicated issue and it needs to be evaluated as to whether a waiver is available or if they are subject to the permanent bar, etc. You should consult with an experienced attorney.
If you travel outside of the US and return on your EAD/Advance Parole, USCIS could find out. If you use your EAD for the form I-9 with your employer, USCIS can find out. If you engage in unauthorized employment while in H-1B, it's a violation of your H-1B status. And as the other attorney said, USCIS expects you to be honest.