Thanks for the detailed reply.
1. What you did with the fish, biowheel, and some of the decor is excellent. No risk of anything other than a slight temperature fluctuation with the fish (we normally suggest putting the tank heater and an air bubbler in the water with the fish). Unfortunately when you rinsed the tank with warm water you probably killed the bacteria that was in the tank (had you used dechlor and it was indeed warm and not hot that bacteria would still be alive). But the filter is the most important thing and the majority of the bacteria will still be alive in there.
2. 3. Lie to them. I'd make up a story and say something like I had accidentally put pH down or some other acidic chemical in there. You want that seed material asap! I understand what the LFS was saying but since you'll have a KH kit you can easily tell if your water is soft (carbonate that is). If the KH is low you can buffer the water with baking soda so the pH will never get even close to 6.0. Then at each water change you simply add a small amount of baking soda to the water (with dechlor of course) and add to the tank. Should take no more than 30sec or so to measure and put it in the bucket, so its no big deal.
Then with the seed material you should see your ammonia start to slowly go down or stabilize, then one day it will quickly read zero.
This is something I think is necessary for people new to the aquarium hobby to fully understand:
Bacteria divide, and as such, for a while you will think nothing is happening. That is because the difference between 1,2,4,8,16,32,64 etc. is impossible to see. They will be consuming so small amount of ammonia that the fish will produce more than they can consume, and your ammonia will continue to go up.
BUT! They are dividing at/near the same rate the entire time (once every 12-24hours is average). What that means is that (space and food not withstanding) it takes the same amount of time to go from 1 to 2 bacteria, as it does to go from 100,000 to 200,000. This is why patience is so necessary at the beginning, and why getting seed material is so vital.
If you start from scratch as you did and assume each bacterium has optimum conditions and divides every 12 hours, in 1 week starting with no bacteria you would have ~4,100 bacteria (using 1 as an example though the fish will have many more on their body and fish waste). This is probably not enough to notice a difference if you had no fish in your tank. With fish, you would most definately still see the ammonia level rise in the tank, and you would get discouraged.
Now, however, if you got that seed material and started with 1,000 bacteria (much more in reality), same conditions, you would have 4.1
MILLION bacteria. 12 hours after that you would have 8.2
MILLION. In this case you would probably see the level stay the same or go down slightly at the end of the week, but by the next morning would see the level dropping quickly.
Both situations described above are the
SAME, the only difference is the amount of bacteria you start with.
So the point of this whole post was to show why we say don't get discouraged and "start over", and when we say stuff is happening in the tank, we mean it really is. Fortunately for you, the majority of the bacteria is still alive and dividing since you kept the biowheel moist, but it would have gone quicker had you not cleaned out the tank.
Now go get that seed material!
