I did “Save project as.” But then as I go along and make edits, periodically have tried to save again (especially since I have had Audacity crash on me before). “Save Project” is not responding–is grayed out. Seems it gave me the option once to “Save Project” after it had not before and has not since.
Are you sure there were unsaved changes? For example, if you you did File > Save Project, made an edit then undid that edit, Save Project will be greyed out because in that project state there are no changes to save since the last save.
If there were in reality unsaved changes but Audacity did not ask you to save changes, then technically it crashed so it should offer to recover the unsaved changes when you restart it.
See above for why Save Project may be grayed. Stop will only be active if you are playing or recording, or pausing playback or recording.