2. Is there a ban on donations from foreign interests to candidates?

Art. 90.2§1, 2, 5, and 6., Election Code of the Republic of Azerbaijan, 2003 (as amended 2019).  http://www.msk.gov.az/uploads/qanunvericilik/Election-code_2020.pdf

Election Code of the Republic of Azerbaijan also prohibits financing of foreign sources in election campaigns as follows:

The following shall be prohibited from rendering voluntary donations and assistance in kind or services to election funds of candidates, registered candidates, political parties, blocs of political parties, and referendum campaign groups:  […]
Foreign countries and foreign legal entities; Foreign citizens;  Stateless persons; [...]  Legal entities of the Republic of Azerbaijan, of which more than 30% of the charter (property) capital belongs to persons mentioned in Articles 90.2.1, 90.2.2 and 90.2.3 of this Code on the day of the official publication of the decision to hold elections;  International organizations and international social movements; […]