Can I take an Advil (ibuprofen) for headache after taking a low dose aspirin?

Yes. Unless a person has kidney problems or uncontrolled high blood pressure, they can still take medications such as Ibuprofen or Aleve (naproxen) even if they take a daily low-dose aspirin.
Yes. Yes, you can. Just use advil (ibuprofen) and other things like them sparingly. They can provide short term relief but also can cause health problems. To help prevent headaches, drink lots of water and consider magnesium supplementation. Also rule out B12 and b6 deficiency.
Probably. You can combine Aspirin and Ibuprofen but they are both harsh on the stomach. Take it with food.