About half of what was written about Sam's shocked me, the other is just plain life. I am headed back to Palau in a week, I lived there in 00 - 01 and even worked for Sam's while I was out there.
I don't know who you dove with at Sam's, but let the battered remain nameless, but let us know who turned the trip around for you. The experience sounds atypical given all of the reviews that pop up about Sam's on this board. Dermott and Russelle would do almost anything possible to make the trip enjoyable.
Rude other divers on the boat - - fact of life. If you want to pick the people on your boat you need to have a group large enough to charter a boat (Sam's even has 4-packs they will use for that purpose). If they wouldn't change your boat after you complained about where they put you that would be quite another story.
Lack of say about dive sites - - somewhat a fact of life. Tyranny of the majority for the most part on dive boats. If you want to pick the places you need to have enough votes or a large enough say. You have to keep in mind you are participating in other people's vacation as well. Unless you were extrememly friendly with the people at Sam's and knew the guide and driver going out it is doubtful they would announce where they were thinking of going a day in advance.
Unable to predict the current at Blue Corner / Peleliu - - fact of life. These are oceanic currents that are none to effected by high/low tide transitions that dictate most normal currents. I dare anyone to say a day ahead of time exactly how you would enter and execute those dives at a precise time. If you told me someone dumped you in the water without checking the current first that would be quite another issue. If anyone ran you against the current that would also be inexcusible.
Lack of Wreck Diving - - Most people head out to Palau for the great biodiversity. There are also 40+ wrecks lying in the harbors as well. Generally, the wrecks are done as a 3rd dive of the day, or when the conditions are too rough to trudge out to the outer reef. You need to find someone with about 5 years on-island experience to do the best wreck diving, and once again this may mean chartering a boat. If someone at Sam's was nice they could have given you a Kayak and taken you to the Chuyo Maru which sits about 1/4 mile from their dock. A nasty surface swim, but an easy Kayak dive.
'Rude' Boat Drivers - - par for the course, mainly a cultural thing. On the flip side these guys do recover your 8-14 bodies from 2-3 knot currents in 5-6' seas every day, like clockwork, so be nice to them.
Lack of dive sites - - tough one..... It takes people so long and so much money to get out there they want very predictable diving. Even if that means 4 good blue corner dives in their 1 week stay. To get a true flavor of the place you need to spend more than a week, and be willing to eat some less than fabulous dives. Spending 90 minutes in the deep blue waiting for pelagics, or scratching a day of diving to wait for the right tides to do one of the tunnels to the inland lakes may be the price you pay.
Lack of WWII sites - - These are really best left for a daylong Kayak or a dedicated boat trip, not really a dive trip. German Lighhouse is easy because you probbaly dove the channel there (Bouy 6 wreck) or one of the wrecks in the lagoon. Most of the other interesting sites are not really close to diving. Once again, if you had your own boat you could put in a dive at Peleliu, stop at the south dock, and spend a couple hours on shore at the tunnel complexes. Then put in a second dive before you head back.
Cattle Boats(?) - - I agree 14 people on a boat is way to damn many. 8 was the right number and the way the majority of the boats are set up. There is scant little room left for spreading out since these are skiffs meant to do 27 knots to the dive site. I still don't think I would equate these to the 36 - 50 passenger varieties you can encounter in the Caribbean.
Jellyfish Lake - - inexcusible. They should just take the group. It is not off the beaten path at all.
Rats - - Typical brown warf variety. Thank your ancestors and the HMS Antelope for that. Think of them as 'Nape Tail Squirrels'.
I wish you had a better time, and that the next time is much better.