I think you need to get out more .........
lets see FORTY THOUSAND A YEAR - well in 10 years time that 400,000 - but some will have died, some will be kids and so the number of voters- spread all across Australia ...... not significant. Of course you could coral them into one spot (maybe with e fence round it - you do fences in Australia - and perhaps some towers at the corners) but they'd only be able to elect 1 MP........
And if a faceless Chinese Corporation says to the Feds " You can't use the Port in Darwin" you just send a couple of police cars around and arrest anyone who gets in your way - unless you believe they 're going to hide a Division of the PLA on the premises somehow.....
"acquiring our own Nuclear deterrent" - just ask the Brits how much they are paying just to RENEW theirs... hell you can hardly afford to operate any conventional submarines right now
"create your own voting bloc by stealth " - ah yes - "before you leave China for Australia Comrade I want you and your family to SWEAR you'll always support whatever politicians President Xi says you should support in Australia" - because all those Poms, Greeks, Slavs., Italians, Islanders and Kiwis do the same................