1. Ask your real estate agent if they were aware, and maybe see if you can get in touch with the seller or HOA for more information.
2. This is a question for a real estate attorney, and the answer may vary from building to building.
3. I am happy to provide contact information for contractors that might be able to help you eliminate the smoke smell issue. That said, I'd definitely suggest speaking with the HOA before moving forward with any renovations.