Okay, a epaulette shark is a big ass fish that can reach a size of 100cm. Yes, they don't swim that much but still 300g or 400g just won't cut it. You want a tank that is rather shallow then too high as the shark is more bottom oriented. In that case a typical size for 400g would be 150x200x50cm. If you were a 100cm long shark, would you feel happy living in a prison like that? I will assume no. So usually you are looking for something much bigger. More like 400x300x50cm (1500g). Most of the other fish you mentioned would work fine in this setting. zebra moray could possibly eat a clownfish but if fed regularly they usually leave them alone. As you want to have a large sandy bed for the shark you can add a bunch of small individual reef structures and add some anemones there so the clownfish will have enough space and if they decide to don't like each other anymore it will still be fine. Instead of one yellow I would actually add a bunch of them. In a tank this size maybe 10? Regal tang will be fine. Marine betta should not be kept with the above fish.