To address one of your concerns, with direct connect (the system used for automatic downloads) your username/password are only passed between Moneydance and your Bank's server, they do not pass through any third party systems.
It is possible to import data into bank and credit card type accounts from CSV files but it is dependent on the structure of the CSV file being suitable. If you bank offers OFX/QFX or QIF formats these are much preferable as they are designed to handle financial data and Moneydance will import them.
I would suggest you download and try out the software in Trial mode, it is fully functional with just a 100 manually entered transaction limit - imports do not count. If you later decide to buy the software the license key unlocks the limit.