Adjustment of Status - I-485

Hi everyone. I have been reading this forum for quiet some time now and it has been a great help. Here is my experience so far. Got married to USC in August 2016( I was M-1 student and my via expired November 2015), sent the application January 30, 2017, got bio done February 22,2017 and my interview is scheduled on April 18, 2017. I haven't received my EAD or AP, nor do I get updates on them on the website. I am now trying to get as much documents as I can. Me and my husband have a joint account together, joint car, car insurance, apartment lease, utility bills, family phone plan, gift receipts, and big furniture purchase receipts for our new house, pictures. What else do you think will help? Also I am confused about our sponsors documents. My lawyer says I don't need to take his tax returns, employment letter(and everything else that's needed from the sponsor) as we have already sent that with the application. Do we have to still take it with us or not? I don't have those documents as I gave them to the lawyer and the originals are back with the sponsor who is out of country now. Also, my husband has never paid for taxes because he was a student and his income was never enough (we are really young)are they still going to ask about his tax returns and pay stubs. I'd really appreciate any help, advise, opinion, experience you had. Thanks a lot.