Hi,

1/ There is no way to turn off hardware acceleration in AutoCAD for Mac, it always uses only hardware acceleration.
2/ I think the key words in OP post are "Gone are the days that you could have an entire set of documents in one file." Looks like OP's DWG files are very complex. Plus they could have some errors in the drawing database.

My suggestion is to test the issue in simple drawing with a few lines, if everything works as expected, than try to run AUDIT command in problem drawings,
If the issue still shows in simple drawings, than try to Reset AutoCAD.
But before this you need to ensure that AutoCAD runs on compatible OS X and has all Updates installed.

Maxim