Adobe Acrobat dc Issues

Hi 

I have recently upgraded from Individual to business license because sales person said, I can do . however, I am unable to do. tried logging a ticket with adobe support and no one responded.

tried pinging through chating, last 3 days, no proper solution . I am already upgraded to business license (1 user)

1) I need to modify the document in flight and resend it to recepient. (recepient has not yet signed yet). how do I do modifying  the pdf and resend.

2) How do I get attachments from the recepient. for e.g. I send the document for signature. then I need to collect driver license, passport copy or some additonal document while signing the agreement. how do I receive the attachment 

3) Adobe sales said, I can handle GEO specific companies in one business user license. I can only use one at the same time. only one login at the same time will work. I am ok. however, I see 4 users were allowed to create. but I am unable to assign the product between users . due to which, user1@domain.com  is able to login and create document. but user2@domain.com is unable to login and use the app. it says, starts a free trial.

any help?