Setting Up My First Saltwater Tank

Today, after much internet research and conversations with seasoned hobbyists, I picked up my first saltwater aquarium.
 
It's a 55g with established live rock and sand. We brought home 30g of established water and I mixed a bunch of fresh. It came with an adorable little true percula clownfish who I'm guessing is male based on size. He's eating well and is currently residing in a 5g bucket with a small piece of live rock, thermometer and small heater set to 78 degrees F. He's looking alright, but slightly stressed.
 
I've named him Krusty; Krusty the Clown. Ha.
 
The tank has been cycling for about 5 hours;
Alkalinity: 300ppm
Hardness: 50ppm
Calcium: 480
Nitrate: 25ppm
Temperature: 79 degrees F
 
I added some nitrate treatment stuff that came with the tank after I did the tests. I'm planning on picking up the other test supplies tomorrow.
 
How long should I wait before adding my clown?
And shouldn't my live rock look more...alive?
 
 
 

What's are the levels of the following:
 
pH?
Chlorine/Chloramine?
Ammonia?
Nitrite?
And the specific gravity?
 
I wouldn't recommend adding Nitrate treatment or any type of chemical like that. Water treatments are good for the water but bad for the fish. From my experience, when I used water treatments, it made my water levels perfect but killed off almost everything in my tank. Just be patient! The cycling process can take about a water, sometimes even longer for saltwater. Your tank should be fine for now, just keep that in mind for the future. 
 
What do you mean by your live rock being more alive? It should be okay UNLESS it smells really bad. If it's stinky, then there's a chance the bacteria living on it died. Live rock tends to be very hearty and can withstand a lot! You're not going to be able to see the bacteria living on it. The rock itself is not alive, it's the fact that there's microscopic bacteria living on it that provides the tank with biological needs. But for the most part, its just going to look like a rock. 

Do you know anyone who can temporarily rehouse your clown until your cycle is completed? Perhaps your LFS? Prolonged stress might be too much for it.

Nitrates of 25ppm seem pretty high to me.   What are you running for filtration?

Live rock not looking alive; that sounds funny  
 
After it has been setting a few months, if you don't toss and turn them, the periphyton will grow on them and  they'll start looking natural ("live")  

Yesterday afternoon all levels were fine, so I acclimated the clown and he's doing well. (It's hard to take pictures of him because he never sits still.)
My dad, of course, surprised me by bringing home a little puffer, which worried me but now he's in the tank and doing fine (and adorable.)
 
Several hours after a water change, my tank parameters are:
Temp-79 degrees Fahrenheit
Nitrate- 12.5 mg/l
Nitrite- 0 mg/l
Alkalinity- 300 KH
pH- 7.9
Salinity- 33 ppt
Specific gravity- 1.024
Ammonia- 0 mg/l
 
So far everything's looking good to my newbie eyes.

These 2 are generally compatible, although there are other peaceful fish that would not be compatible with the puffer.  I like that your nitrates have come down, but would still keep monitoring them.  More flow around your liverock with help reduce nitrates.

What types of fish aren't compatible with the valentini? I know that she'll nip at long fins, munch on shrimps/corals and fight with other puffers. So far she and the clown are getting along swimmingly (ha). Nitrates are currently at 10 mg/l.