I've got a WB25 as my main display right now.
Current Inhabitants:
- Possum Wrasse
- Yellow Clown Goby
- Firefish
- Royal Gramma
- Randall's Pistol Shrimp
- Skunk Cleaner Shrimp
- Assortment of small hermits (Red Tip Dwarf, Blue Leg, and Scarlet Reef)
- Assortment of snails (Trochus, Nassarius, Cerith, Stomatella, Bumblebee, Tiger Conch)
- Asterina Starfish
- Tiger-Tail Sea Cucumber
- Porcelain Crab (Lives in my RBTA anemone)
To answer your questions, I'm going to agree with the above comments that 7 fish is probably too many for this size tank. I think it could be done, but you would need to select non-aggressive and small fish and add enough rockwork with enough hiding spots that they could all have their personal safe area in the rockwork.
The 4 fish I have now feels like a good amount and at most I'd only want to add 1 more fish to the tank in its current state.
I can't speak to all the fish on your list, I will say that for me personally I specifically avoided getting clownfish because I've heard plenty of people say that once they mature and are ready to breed, they can become very territorial. I didn't want to deal with having to rehome my fish if/when that happened.
For the royal gramma, mine is a newer addition to the tank but seems pretty chill and likes to just hang out near it's hidey-hole and watch the goings-on in the tank.
For wrasses, I personally have a possum wrasse who I adore and is very chill and just likes to cruise around the tank. My alternative wrasse was a pink streaked wrasse (aka cryptic wrasse) but in my experience those are harder to find and more expensive (but very pretty looking). wrasses are also great for pest control.
While not a black clown goby, I love my yellow clown goby. He likes to perch around the tank and just adds some fun character. He'll swim right up by my hand too at feeding time.
I'd definitely recommend any/all of the 4 fish I have for your tank.
For invertebrates, my main limiter is my wrasse :p I'd love to get me some small sexy shrimp because I think they look adorable, but I know my wrasse would find them a tasty snack due to their small size. Anything larger than maybe a half inch I expect would be perfectly fine. Other than that, I have personally avoided emerald crabs since I know they may eat small fish once they are large enough, and decorator type crabs because I don't want them messing with my corals. I would consider both emerald and decorator crabs if I had a larger tank that I was sure would supply them enough food to forage that they wouldn't go after fish.
My personal philosophy with my tank was Variety, Chill, Small, and Natural.
Variety - For me, this means I don't have any specific centerpiece corals or fish at the moment. I prefer to get a mix of animals (see my variety of hermits and snails) and I enjoy each part of my tank being unique and having its own cool little gems and surprises.
Chill - I wanted a peaceful tank, so no fish that were known to be aggressive or become aggressive as they age.
Small - All my fish could be no bigger than 3-4 inches in length when full grown. I also specifically avoided active fish such as dwarf angels for this tank (looking at you flame and coral beauties) because I knew I would not have enough swimming room for them as they got bigger.
Natural - For me, this means putting the needs of my fish first. For my tank, that means a good pile of rocks with lots of hiding spots. I might not see my tank inhabitants as much, but I know they're happier, less stressed, and feel safer and more comfortable. It also means only smaller fish because larger fish (e.g. tangs and larger angels) somehow break the immersion for me because most tanks feel too small for them and it feels like a tank and not a piece of reef. I also try and run my lighting a bit whiter as a personal preference for how the tank looks.
I know I'm kind of rambling, but hopefully this gives you some ideas. I'd highly suggest deciding what kind of tank YOU want as it will help make some decisions for you about what you can and cannot put in your tank.
What are things you "Must Have". If you have something you absolutely want, research it's care and eliminate other stuff or animals that won't work with that.
Other helpful questions to ask yourself:
Do you want a variety or is there a fish/coral/anemone that you want to have as a centerpiece?
Do you want a more chill or more aggressive/predatory tank?
Do you prefer more open or closed rockwork?
What kind of corals are you hoping to keep (if any)?
Whew! That was a lot more than I expected to write. Hope it helps and let me know if you have any questions
