yes, those are all good for seahorses, but seahorses aren't necessarily good for all of them. Seahorses latch onto things with their tails (these are known as hitching posts). Any branching coral is a good hitching post, but if you have photosynthetic ones, such as gorgonias, the seahorses will hitch onto it, and eventually kill it by depriving it of light. I'd say the easiest way to maintain a seahorse tank is to have only fake decorations (except maybe mushrooms). This way, your tank itself is low maintenance. Seahorses are such high maintenance creatures that they require a lot of time. It would be even more time consuming to have live corals as well... just my opinion. That's how my seahorse tank is setup anyway...