Welcome to MAAST, you have come to the right place!

Yeah, I second what Ram stated. I did the same thing as you did when I first started. I got a sand sifting starfish with the clean-up crew I purchased. The reason any animal "sand sifts" is because they are looking for food. If you don't have an established sand bed, there is of course no food for it. Even if you did, you might not want to keep it as it eats all the good things that make a live sand bed functional. I would go with some snails or a cucumber to work your sandbed once you get it a little more established.

The best way to get it going is by either seeding it with some uncured live rock which you can't do now that you already have livestock in the tank, or by trading sand with people who have established tanks. There are a lot of members in the Austin area that I'm sure would be glad to trade a cup of sand with you. Sometimes people weed out there refugiums and their macro algae is filled with pods and critters as well.

As far as the fish choices go, the mandarin is of course out of the question for awhile. They eat pods and need a well established food source. The wrasse is along the same lines. I have one and it is constantly foraging through the rock looking for pods and other critters to chomp on. I know that my pod population in my tank is much lower than it used to be because of it. As far as angels go, I wouldn't recommend the flame. It is a beautiful fish, always been my favorite, but they need ideal water conditions and they have not fared well over the past year or two going through capture and shipping. They seem to be ok for awhile, but then die. There are several others out there that are good choices. The coral beauty is one and their colors vary some from fish to fish. I have a flameback angel and like him a lot. There are two different ones, an African and a Brazilian, one being much rarer than the other and of course more expensive. Hopefully this helps and keep the questions coming! :-)