I want to know if I’m legally married ?

Without a divorce or annulment or his death you are still married

Do we need to have a lawyer for removal proceedings if my wife is currently in the process for new applications with uscis?

I doubt you will get any lawyer in this forum or otherwise to say your wife should represent herself. Furthermore the Judge Will not allow it...

Generally it means your passport number. Advance Parole number is your file number at Immigration.

Can I apply for US Citizenship?

Since you arent living with your wife you must be a green card holder for 4 years and 9 months before filing citizenship. You arent eligible after...

Does aging out prevent my daughter from getting a green card ?

If she isnt covered by child status protection act you would need to file a separate I-130 for her which will fall under F2B category.

H1-B - incorrect answer to "more than 25 employees" but sent the correct filing fee?

Might cause a kickback as they would expect 1500 for more than 25 employees. Could at a minimum cause an request for evidence.

Removal of 2 years conditions on permanent residence

Proof of joint bills in both places and file where you reside at time of filing.

FILING ADJUSTMENT OF STATUS AS IMMEDIATE RELATIVE WHILE I-130 IS APPROVED AS SPOUSE OF LPR ?

You file the I-485 with among other things the I-130 approval and a copy of his naturalization certificate.

After a denial of the citizenship for failure to file taxes , is it possible to file back taxes and appeal the decision? ?

You need tonfile back taxes and then reapply for N-400. Appeal wont work - they were correct in denial at time of decision.

Spouse's (sponsor) expired passport/ interview next week

Is this a US Passport? Was he born here and have a birth certificate? Did he naturalize and have a naturalization certificate?