lovely

Yes: You can attend the stamping interview with ~8month validity. Yes: You can file earlier for your extension of H1B and then go for stamping, as long as its not an emergency/urgent requirement to travel, its recommended to extend and plan so you can be ready to deal with any delays on passport return and/or queries.

You're just in the waiting game, they probably will reach out in case anything is required from you and/or employer/client etc.

You can work to furnish all those documents and attend their in-person, if you look through the forum there were many cases with in-person being called after dropbox and they eventually travelled, you might want to discuss the case with your employer and request for additional time/documentation/support while you're going through this process.

Please reach out to your attorney so they can represent your case. If it can be overturned? that completely depends on your profile, ban is not something we see on a daily basis but you have your chance to represent via attorney.

You might want to cancel that ds160 and create a new one, try to call them and fix that one question but its always better to fix a known issue instead.

Reach out via email/phone and explain your situation & reason, they might ask you to do a dropbox eventually

If its not an emergency then its better if you schedule an appointment and then proceed with peace.

You need to follow the standard procedure, "lost-passport" & fill out all documents/requirements w.r.t lost/stolen/damaged category & then complete your DS-160 and furnish your reports/complaints as supporting documents. USCIS has a requirement to furnish "ALL PASSPORT COPIES" NEW/OLD, "ALL VISAS ISSUED" VALID/EXPIRED etc, now when you cannot furnish what they wanted, please supply the solid reason on why exactly you are unable to do so.

You should be good, there were some travelers like you that did not have any issue however, each case is different, if you're not in an emergency then renew and visit.

It could be considered as "no show" or might result in RFE since they would be expecting 3 passports and you changed your mind and will submit only 2, so, if you wish to use the same slot then if they ask for 3rd passport as part of RFE then please be prepared to make travel arrangements for your daughter to travel and attend dropbox/interview on requested date. You may have to cancel all 3 & reschedule for 2 only and even then be prepared to identify how your dependent daughter is able to stay without parents in US.

You have to follow the standard protocol and apply for a new passport with reason lost/stolen & get some documents from Immigration authority that it was lost at their facility and furnish those to your police complaint as evidence, then schedule your stamping appointment along with all documents you acquired while your passport was re-issued. No, Indian govt will issue a new passport only, visa is subject to applicant and has nothing to do with them.

Infants are usually were not called often at the time of personal interviews, so your infant's birth certificate and additional documents should be good, dropbox is case by case and you will not know it until you paid the fees and answer all questions listed in their website. Since its the only application that requires stamping you need to complete application for your new born.

Yes, there have been few cases where they could not accept certain documents unless the applicant is in home country....in your case its NOT, they can reject applications for a variety of reasons and not just by degree certificate validation...its better if you stay in London and enjoy your work....you're in good shape with your residence permit and focus on your British citizenship...GC is a long way to go unless you intend to go through it.

Probably, they will verify your passport and either cancel by asking you to get new passport, if you think logically the passport was valid at the date/time of application and invalid at the time of appointment, so its better you use new application along with new passport for a smooth sailing.

You could call their 1800 number and check if they are able to make some modifications or even validate, if not you could ask them how to proceed, the right thing is to disregard and start a new one as its illegal to furnish false information either knowingly or unknowingly.