I currently have 4 clown loaches. They are very sociable, and they are out playing all of the time. They have a lot of shelter among the rocks and plastic plants. They do nap alot during the day, but if they hear me in the room, they wake up and start to look for the food. Mine will eat anything. One of the LFS has a snail problem, and they love to give me a bag of free snails. It's amazing to watch this fun loving little guys turn into hell bent hunters. If there is a snail in the water, they will hunt it down. My clowns will eat any commercial fish food. Pellets, flakes, freeze dried, etc. They really like veggies also. I will give them spinach, zuchini, cucumbers, and other soft veggies. I have a small rock, and I attach the food with a rubber band. I also will feed them freeze dried kelp the same way. If you want to be entertained for a while, cut a piece of cocktail shrimp into a medium size. Make it small enough for them to move, but not small enough to swallow whole. One fish will grab it, and try to run with it. The other fish will try to steal it. They will all get a few bits, and they get some good exercise.
Mine are not shy at all! They seem to like me. When I feed them frozen food, I melt it first in a small plastic cup. I'll pour a little bit of the frozen shrimp and water into the tank. They swim right up to, and sometimes into the cup. Some times when I'm cleaning the tank, they will try to graze on the hair on my arm. It can hurt when they get one! If sit in front of the tank, they will swim to me! When it comes to clown loaches, I think it's safe to say that there are no specific rules. The clowns personallity and behaviour varies almost as much as humans.
With most social fish, the more you have, the better. Same thing with the hiding spots. The more the better. Give them time to settle in, and they may show themselves more. Then again, maybe they won't!