Hi Ronsky 101,
Palau is mainly about big stuff: sharks, mantas, napeoleons, bumphead parrotfish, dogtooth tuna, groupers, turtles, cuttlefish, big schools of jacks, barracudas. However, there are still some small critters to discover: leaf fish, some great nudibranch, ghost pipe fish, mandarin fish.
If you would like to know how is a liveaboard experience in Palau, read our weekly
trip blogs in Palau.
Regarding the current, you will mainly find currents at Blue Corner, Ulong Channel, and Peleliu which is the best time to dive those sites since you will find big aggregations of sharks. The currents are usually easy to handle so you shouldn't be worried.
As nudisusie says on land prices are similar to the USA since the local money is the US dollar however, on a liveaboard everything is included so you won't have to worry too much about the cost of living in Palau.