Very interesting points Greg .... a few more to ponder ....
Why was it called New South WALES ? not New Britain ... guessing that the island of New Britain off PNG wasn't named at that time & "New England" was already taken by the yanks ?
I think you have to include Queensland as Capt. Cook named Redcliffe & Deception Bay (both just north of Brisbane). Redcliffe was the first white settlement in Australia but quickly failed so they moved it to Sydney Harbour (the 2nd settlement). The remains of Queensland's navy (3 ships) lies at the southern head of Margate Beach, Redcliffe -- don't know if there is anything left now but was recognisable as iron-ship remains in 1970.
Northern Queensland becomes a seperate state (a very old battle still being fought) .....
Originally the Queensland / NSW border was to be west from Coffs Harbour but was moved north to the Lamington Plateau escarpment as a favour to some corrupt politician.
Will the ships have names more in keeping with ties to Britain ? ie HMAS Whitby (where Endeavour was built) or HMAS Chatham (biggest RN Dockyard, there is a HMS Chatham) ..... HMAS Golden Hind
Please tell me that most of the smaller ships like Destroyers are to be paddle-steamer types
If successful, the Eureka Rebellion would have changed Australia's politics drastically - probably forging closer ties with NZ, Communism in Russia (more Aussie troops sent there in 1920) and cutting ties with the UK (but not the Trade Union Movement there) & making Oz a Republic fairly soon. Even today Tasmania should be part of Victoria not a separate state :-((.
We come back to the usual problem -- population - we don't have enough people to man anything but a small navy & can't hope to patrol much more than our own coastline unless bolstered by the RN -- gold rush pays for mecenary sailors ?