I will still only have a total of 9 dives logged (4 being in 20ft of water in a lake). Do you think this would prepare me to do the Molokini Back Wall, Molokai, or Niihau?
No, don't know, NO.
The backwall is a live drop meaning that the boat doesn't anchor. Coming up you have to be able to hold position for a safety stop with no visual reference or anchor rope to hold onto. And know how to reboard the boat while it's likely pitching and tossing in open water. Gettting hit by the ladder will ruin your whole year.
There are currents there that will take you along the wall faster than you can react and often upwellings, get caught in one of those and you're at the surface before you would know how to react at your skill level. And there's no visual bottom in most areas - a lot of it is around 200'.
Stay
inside the crater at your experience level, there's a lot of interesting things to see, fish, prolific coral, often white tip sharks.
Ni'ihau is out of the question at your experience level. But the boats won't even be running over at that time of year so it's a moot point. It's a rough, long, ride over and back. Unless you're really good on boats, you'd likely feed the fish one way or the other. You're an awful long way from a hospital/chamber if you get bent also. You would need better skills at Ni'ihau than to do the Molokini backwall.
Wait a few years, get some experience. No point in getting hurt your first trip out doing dives over your skill level. There's an awful lot of good shallow diving on both islands. Be sure that you tell any operator you're diving with how many dives you have, most people will have 5-10 times more dives than you before they get their AOW so it may be assumed that you do also.
Nothing personal but you're way underqualified for the dives you're mentioning.
I'm not PADI but I think you can do the classroom in MA then get a referral to do the dives in Maui with just about any of the operators. I know Extended Horizons does check-out/beginner dives in the afternoon just off the coast somewhere - when the tradewinds pickup in the afternoon most boats stay near shore. You can also do some easier, personalized shore diving with Shaka Doug or Maui Dreams Dive Co. in the Kihei area.