Yes, I realize I have gone against some of the advice I've been given here, and if the fish all die then I will eat a hot plate of crow and have it on my conscience. I knew I would probably get a good stern talking to, but if you care to read, here's my reasoning...
I spoke with the owner of the pet store about the situation and he was the one who helped me pick out the fish. All of his tanks are separated so he can monitor new arrivals, which was one reason why he advised against taking any of his platy stock - he wasn't confident they were healthy and wanted to keep an eye on them for a few days. This tells me he's concerned about the rest of his fish by keeping them all separated when they arrive, and he wants the fish I buy to stay alive. Through the various articles and forum topics I've read, none talked about hydrogen peroxide. Since the owner told me he regularly uses it in all his tanks because it helps with oxygenation (correct term?), AND since the group of fish I would be taking home are going to help the initial cycle, he recommended I use a little. I saw no harm in taking his advice, since he uses it in his tanks and I saw no adverse effects.
When he mentioned possibly adding the dwarf gourami to the group I was getting, I did ask him extensively about it because I'd read how gouramis were aggressive and shouldn't go with the peaceful fish I planned on stocking. He told me that yes, most gouramis are aggressive and he wouldn't recommend any other kind than the dwarf flame gourami I eventually chose. The proof was also in the pudding - he had a few mollies and I think a couple of swordtails in the with the dwarf gouramis. All the inhabitants seemed calm, I saw no aggressive moves and no nipped fins or anything.
And as for the goldfish, it was my daughter who saw it and asked for it. Up until then I had left it up to the owner to pick out the hardiest fish for me and I didn't want to tell her she wasn't allowed to pick even one fish. Call me a sucker.
As for the water going in with my tank water, that was a judgement call. I was hoping that the water from the store (since the owner seemed very meticulous about his stock being healthy) would have some bacteria to help with the cycling. Perhaps I am dreaming, but at 10:30am (before adding fish) there were no signs of nitrates - at 5:00pm, it was clear there were nitrates in the water.
So that's the gist of it, sorry if I disappointed anyone. Guess my moxie took over
TODAY'S UPDATE:
At 2:15pm, all fish are swimming around actively. Sage fed them a small amount of flake food and they ate well. Whiskers the gourami wasn't shy when Sage was in front of the tank, which is a change from yesterday when he was rather shy of movement near the tank. I have been watching carefully for signs of aggression on any fish's part and so far all seem to get along fine.
tested the water:
ammonia @ .25
nitrites @ 0
nitrates @ >5, but less than 10 - definitely darker than yesterday.
THE EXCITING PART:
One of the calico mollies was pregnant and apparently gave birth. I saw one tiny little baby (less than a half inch, head to tail)! Who knows if it will be able to avoid being gobbled up, but I thought it was rather neat and Sage was really excited to see it swimming around the rocks.