1. erratic
"Police stopped him for driving erratically. His heart beat erratically. The machine is working erratically - there must be a loose connection. His breathing was becoming erratic."
Your breathing is erratic
2. inconsistent
Whenever a company policy is changed without warning, or is inconsistent, there will be negative reactions.
These findings are inconsistent with those of previous studies.
Her reasoning seems inconsistent to me.
3. inconsequential