As for the gravity readings, I wouldn't worry about it. Assuming this is an extract kit, for the OG, the only way you could be off would be if you didn't use all the extract or your volume was significantly off. What probably happened is that its really difficult to get the extract and water thoroughly mixed after you topped off the recipe and the sample you took was a little more water, a little less extract. For the FG, it is common for extract beers to end up a little higher than expected. No worries, 1.024 is well within the range for this style (according to the BJCP style guidelines, that range is 1.018 to 1.030, so 1.017 would have been too dry).
For adding the yeast, I would boil some water, let it cool, then rehydrate the yeast in that. Same for the coffee - boil the water, let it cool, then cold press the coffee. I wouldn't worry about sanitizing the coffee beans, I guess.