You can change INTU.BID (bank identifier) on the Settings tab. Click the Look Up button to locate your bank. If your bank is not listed, keep the default value 3000 (Wells Fargo). This setting is only for the QBO file - you will choose actual account during import.
Once you load the CSV file, click the Review Mapping button and assign correct fields on the Sidebar (in the Mac version change the mapping right on the sidebar.
To import all transactions, make sure that the Reference dropdown is set to "do not use" or to column with unique values.
QBO files doe not support split transactions. Use IIF format with CSV2IIF for that.