Cockle Bay Marina is one of the nicest wharves to start a cruise from, being in the heart of Darling Harbour. Perfect for lively charters wating to grab dinner or drinks at the many waterfront bars, clubs and restaurants. The Sydney Convention Centre is also easy walking distance. Sailing boats generally can't access this wharf due to Pyrmont Bridge.
Yes, wharf fees start from around $30 per stop.
There is no street parking but there are many paid car parks nearby on Sussex St and at the Entertainment Centre.