salt water for a novice?

First a "cleaner shrimp" is not a reference to its tank cleaning abilities, but rather to the fish cleaning abilities. A Cleaner Shrimp will literally eat parasites and dead scales off fish in the tank. They do forage a bit too, so do a little tank cleaning, but non-cleaner shrimps can be even better tank janitors. I note this simply by the way you reference the shrimp. A peppermint shrimp is a better tank cleaner than a cleaner shrimp for example, and is more peaceful, cheaper, and able to be kept in groups.

Tang do need a larger tank.

Cost of setup can be several hundred dollars. The larger cost is in live rock, salt, and higher water movement needs. Live rock is vital on keeping a long running saltwater tank with less maintenance than without it. Some people do the Jaubert Method which is less rock intensive, relying on many inches of sand to do the trick instead. It can be cheaper, but has its drawbacks as well. Expect to spend at least $500 on a basic setup, or more if you do not look around for cheap items and only buy new. Monthly costs vary, but maybe $50 on average.

As far as starfish, a fancy brittle star is OK but some of the hardier sea stars, like a chocolate chip star can get large and tend to eat just about anything including other desirable inverts like snails, urchin, coral, etc. Other starfish, like a linkia, are very sensitive to changes in water chemistry and difficult t keep. So other than maybe a brittle star, avoid starfish as a beginner.

You are right to be nervous about touching some coral. It is easy to bruise some coral, and some can even hurt you (I've been hit by a fire coral - OUCH). Most have a base to which they are already attached which allows for safe handling. Others have a calcium based stem with no flesh on it that make it safe to handle (like torch corals). All coral acts and grows different than other types of coral. There are several categories, like soft corals (no skeleton - only flesh), Large Polyp Stony corals aka LPS (have a skeletal base with large fleshy polyps and larger mouths), Small Polyp Stony corals (are visibly hard with a thin fleshy growth over the skeletal base and small polyps with small mouths), etc. SPS tend to be more difficult with high light requirements and specialty liquid foods.

The stocking plan you currently have on fish is perfect for a 40-50 gallon tank. Maybe add a tailspot blenny or other small blenny, and then you are pretty well stocked with little room for future additions.

Set the tank up and cycle. Get a test kit to confirm when ready for fish. The cycle is in the live rock, so with lots of live rock that is fully cured, you can sometimes add ina fish a lot sooner than 3 months. You will hear 6+ months on several more sensitive species as some fish need a mature and stable tank before one can contemplate keeping them.

Weekly water changes, partial. Exact volume will be determined by your water tests.

Know for a successful aquarium as a common setup you want about 1+lbs per gallon of live rock and 15-30 times the volume of the tank in water movement per hour. Add all live rock BEFORE fish. Confirm the tank is cycled

As you can see there is a lot of information and little room here. Get a few good books. Below are some suggestions:

http://www.amazon.com/New-Marine-Aquarium-Step-Ste...

http://www.amazon.com/Conscientious-Marine-Aquaris...

http://www.amazon.com/Ultimate-Marine-Aquariums-Sa...

Some good reference books for coral and fish:

http://www.amazon.com/PocketExpert-Guide-Marine-Fi...

http://www.amazon.com/PocketExpert-Guide-Marine-In...

As a novice, or even a person with a little bit freshwater tank experience, stay away from saltwater tanks. Rather more costly to set up and maintain, and you're going to suppose so much worse if a $50 fish dies than a ninety nine middle. If you want some fish which might be fun to look at, get some younger oscars and watch them grow. In less than 2 years ours went from 2 inches long to 9 inches long. Apart from fish pellets (after they had been huge enough) we gave them the little frozen salad shrimp which ended up quite a bit cheaper than the reside fish which can be encouraged. They lived plenty of years unless my husband sprayed air freshener to almost the tank. Also, undeniable historical original goldfish grow like crazy if in a just right sized tank. Do some studying on-line earlier than you are making your decision. Some fish are much more forgiving and tolerant of water conditions and temperatures. Keeping a tank crystal clear will not be easy.