The first question about windows10,I'm not sure about.You can make global edits easily to any attribute of any position.I personally lowered every linebackers jump by 30 and defensive tackles block shed by 30.
The draft class shows up when you go into the franchise file and can go into anytime.I believe there are draft classes you can drop to save some time and edit from that if you wish.
There is a function that allows you to mass delete the UDFA's during preseason.
You can make schedules also.I put in the real schedule.Takes some time but not that hard to do.You can also change teams playbooks to reflect a change from 4-3/3-4.