You will start and be able to add attributes - the buckets vary depending on position.
You cannot max out at a 99 this year, not close. So even if you max out, you will have to earn more attribute bucket slots to fill up by playing
MyCAREER and/or MyPARK. You will have to also
EARN every badge you work for, but can upgrade badges once you receive them.
You can create players like point-forwards, but their play making maxed out won't be as high as say a PG. And rebounding for a PG won't be as maxed out nearly as high as a center. This, on top of the badge system, helps individualize players even further. Something the team spent a lot of time focusing on.
Hope that helps.