In general we take around 7-10 working days to complete I-485, and our fee is $1000 for the principal applicant and $500 for each dependent.
Write the applicant's name with a pencil.
Please do paper clips or nothing.
No need to submit all the pages, the bio pages including personal data and emergency contact page as well as visas will be fine. Moreover, please do not forget to submit all the old and new copies of passports for both the principal and derivatives.
Yes, the contract (retainer) covers RFE as well. No need to provide an additional fee for that separately.
The signature of the Affidavit of Birth does not have to be the same as in the passport. She will be able to sign as she wishes in both Bengali and English.