Here is the settings I used for career mode to avoid the superhuman Justin Thomas issue:
CPU Skill - 82%
CPU Event Skill Deviation - 25%
CPU Round Skill Deviation - 10%
CPU Attendance - 90%
The other trick is to just play 2 round events. I know it stinks, because it's not realistic, but you do still get a cut after round 1, and the scores I would get would be pretty realistic and competitive.
And good point about the lack of playoff...that's another thing that Tiger Woods 14 had...and it even had specific types of playoffs depending on the event you were in. For example, if you tied at the end of the US Open, you'd have to play a full 18-hole round to decide the winner.
To be fair, it was dumb that EA removed playoffs from Rory, too...