I dont agree with you in the slightest here BaconJack regarding a second coaster for LPM
Luna Park Melbourne has had 2 signature coasters since 1923. Right now what is missing from their lineup is a modern steel compact coaster- one that will look good from a distance and add to the St Kilda skyline but also give a decent riding experience. There are plenty of coasters that could be developed to fit in the space they have- something from Gerstlauer is the obvious choice.
With good planning and a customised layout, they could fit a decent coaster in and potentially another flat or even a dark ride. The potential is actually quite large.
Consider the above photo from the mid 70"s. LPM fit into the current Metropolis envelope the 1923 vintage wooden Big Dipper and also the River Caves dark ride. At this time the park also had the Giggle Palace, the Rotor and the Ghost train in operation.
Yes there are definitely rides that need replacing from their current ride lineup.
The rides you quoted are probably about right. The AS1 is a piece of garbage now and a new modern simulator would be just the ticket.
As much as I love the Enterprise, I too feel that its days are becoming numbered ( Sorry @HussRainbow87) A Zamperla Super Air race would be a good replacement- the newer upgraded model would be that little bit different from Pandamonium at Dreamworld. Alternatively , A Zamperla Endeavor would almost be a like for like replacement.
The Meisho Swing ship is also ripe for replacement. A Zamperla Disk'O" would be an ideal replacement and would fit into the same ride envelope.
I would also replace the current Ferris Wheel in favour of a newer and larger model- the Sky Lab wheel at LPS is one of the most popular rides and a similar sized wheel would have a similar attraction in St Kilda.
Finally, I think a Huss Rainbow type ride would be the perfect addition to LPM. These rides deliver a good amount of thrills but are great for entire families to ride. Pretty sure that Huss Rainbow's are no longer in production however ( @HussRainbow87 you can provide a definitive answer here) most major ride manufacturers have a similar type of ride that could be sourced.
However, the biggest change that needs to happen is that the park desperately needs an owner who is willing to invest in the park. A 5 year plan for overall improvements ( not just ride replacements- general park and facilities improvements ) is what is really required.
LPM is very small. What it does have is its sense of history and I think the park undersells this to a major extent. Its never going to be a major player like our big parks but it certainly does fill a niche for the Victorian public. It is an icon of Melbourne and is well located on the St Kilda seaside to take advantage of this beach and holiday atmosphere. Other than LPS, there is simply no other park like it in Australia.