Any suggestions for a good article explaining color management/profiles
in Photoshop?
Does it replace Adobe RGB 1998 under color settings
No, no, NO! Don't do that! That would lead to disaster.
You don't set the monitor profile in Photoshop, you set it in the OS and Photoshop reads it from there.
Go to the Apple menu > System Preferences… > Displays > Color > select your calibrated profile there.
As a reminder, when you calibrate, be sure you select 2.2 gamma and 6500°K temperature.
Neil