You can still use your secondary basic attacks, spells, buffs, skills.
And what stops you from using them now?

All of this is simply more convenient with auto-attack simply because you do not have to return to Row 1 Space 1 to throw that regular attack in there every time.
Convenient? Assign a separate button for the basic attack if this is such a huge headache. That is convenient, and doesn't require any massive changes.