In TextEdit or similar editors, is it possible to go to a previous bullet's indent level without a bullet?
Many WYSWYG text editors and word processors try to anticipate your formatting intentions.  It takes a bit of work to overcome this at times, selecting lists, deselecting lists, adding formatting after the fact, etc.

For a bit more control while working, you can manually insert bullets in your text along with using tabs.  See Screenshot.  Not using the list but rather setting your tabs manually and typing the bullets manually is a bit more work at first but gives you the control you need.  This should work in most text editing environments.

option ⌥+8 will make a text bullet • (You can use any character you wish too either by typing the key combination or using the Character Viewer)