Seriously, selecting a miscellaneous quest that I know should have a quest arrow (in this case, get work from the Companion leaders) causes no quest arrow to pop up, no matter what combination of quests I select, and the others, which may or may not have quest arrows, don't have any quest arrows appearing. Regular quests work fine in this regard, but Miscellaneous do not. Verifying game integrity finds nothing wrong, and does not fix the issue.

Sometimes when I activate too many quest markers at once, some of them will appear on the world map, but not on the local map and not appear on top of the quest characters/doors.

Go to your journal, you'll see all the quest items on the left.
When a quest is active, it will have that little arrow symbol on it. Make sure the Miscellaneous section has one.
You can have as many miscellaneous items selected, but if the section is not selected, nothing will show up.

Hopefully that solves your problem.