This information can be obtained by contacting the managing company for the HOA or by asking a title company to obtain the information for you. HOA's must file their covenants with the county, so they are of public record and title companies can obtain this information. You can also obtain it yourself by looking on public records. The only way to find out if a property is occupied is to ask the listing agent or drive by the property, sometimes it is obvious if it is vacant.
The best way to get this information about monthly dues is to call the HOA company/management office and ask them directly. Very often the information listed with the property by the listing agent is incorrect or missing at all. Buyer's agent can assist a buyer getting this information at all. The only way to find out if the home is occupied is to contact the listing agent. Hope this helps.