2000 Ford Explorer Interemittent misfires?

After sitting all night, the engine will run rough for a minute or so, but it clears up after 30 or so seconds of driving.

Also having random misfires that may or may not be related. Check engine light was on, code indicated Cylinder 3. Pulled the plug and checked, looked OK so I replaced it. Cleared the code, a week later it was Cylinder 4.

Misfires happen very infrequently at any speed, but are definitely more consistent in the first 30 seconds after starting the engine cold.

Perhaps completely unrelated, my idle speed in park and neutral is 1000-1500RPM, but drops to ~900 when put into gear. That seems abnormal to me.

Any ideas?