The Australian Navy needs a modernisation. Our main gun's don't fire quick enough to stop an incoming missile if it has gotten through the other defenses and they dont fire quick enough for NGS. Our submarines are much inferior to those of other navies. They do not have VLS which can prove fatal. The navy says that they dont want VLS with tomahawk missiles because it will cause an arms race in our area, but we could use UGM-84 Harpoon and Exocet missiles. Our LHD's arn't well enough defended, with 4 30mm cannons, that isnt enough, 4 phalanx CIWS,1 sea sparrow missile launcher and 4 harpoon boxes is sufficiant I think. Our patrol boats cant really defend themselves in an air attack and I would like to see a VLS fitted but it is probably not needed. Our Balikpapan class needs more than two 7.62mm GPMG's in an amphibious operation. Anyway I couldn't have a go at our AWD's because they have a great armament. I think the RAN needs a bigger defence budget which we can all agree on.
The LHDs will be escorted by AWDs, FFGs, upgraded ANZACs and in the future the SEA 5000 Next Generation Combatant (that may very well end up being more capable than the AWD) they will not be defenceless by any definition.
Patrol boats are, well, patrol boats, not corvettes/frigates/destroyers/Imperial Deathstars, they are just EEZ patrol vessels. The current ACPBs are aluminium and as such have a limited structural life, there is simply no point going to all the time and effort required to turn them in to "uber" missilecraft. Besides they are due to be replaced under SEA 1180 with a much larger more capable platform.
On the subs, the Collins Class are regarded as one of the most capable conventional subs in the world, many of the designs the uninformed masses are suggesting as suitable replacements are in actual fact less capable than the Collins. Oh by the way our subs have used Harpoon since the preceding Oberon Class, and why on earth would a sub ship both Harpoon and Exocet?
A bit of friendly advice, try googling your ideas before posting them here as the information is easily available and it will stop you looking like a clueless kid.