I admit, I don't usually put too much thought into my fermentation temperatures... but my brews stay in the basement where the temperature is pretty steady and in the mid 60s (plus it's nice and dark down there).
As mentioned earlier, that trub (gunk) at the bottom of the fermenter is normal, and should be left behind when bottling.
I don't think you did anything wrong with sanitizing. Many of my beers ferment "aggressively" for 2-3 days or so, then they slow down, and then the bubbling stops almost all together. This doesn't necessarily mean that the fermentation is done, it just means that the yeast is no longer producing enough gas to create high pressure, hence why the bubbles stop. You should use a hydrometer, measure after 10 days or so. Then, measure after the 11th, the 12th, and so on. Once the gravity has settled for a few days in a row, that is when the fermentation is done. There is no real harm, however, in just trying to play it safe. When I first started, I never measured gravity, so I just waited a few extra days longer than instructed in the recipe, that way I was more likely to catch the batch after fermentation was complete.