In defense of Als287, he was only acting on the information she was given. Se did come here for help, even if it was too late. I think we should be a little more considerate since she was, after all, led astray by the people at his fish store who should of help him to begin with. I think enough people have already told her the error of her ways and maybe more people should be helping her with the problem she came here with. I know from reading a lot of help posts that the first thing people do is scold them for their errors. Everything is a learning experience for people that are new to things. It's the same everywhere, not just fish keeping. People only gain knowledge through trial and error or other people pointing them in the right direction.
I should clarify, my comments were meant more as comment about the fish store salesman. Anyone new to the hobby is apt to fall prey to poor advice, and someone who has never looked at a 6 inch Oscar would not necessarily realize how big of a fish that truly is. Additionally being told that an Oscar will only reach about 6" didn't help matters either. The Oscar Tank size debate usually starts at 55g and goes up from there.
The small white Bugs are most likely copepods as mentioned, they are highly common and harmeless. I have them in all of my tanks, but do tend to see them more in the tanks with high organic levels. They can essentially be disregarded as an issue in the face of other more pressing issues.
The rest of the situation requires pretty rapid action. Seldom are Oscars sold smaller than 1" and really a 2.5 " Oscar in a 10g tank will prove too much. Since Oscars grow at roughly an inch per month (Sometimes less but not always) there is really only a few weeks to find this fish a home and then find a fish more compatible with that size tank.
Dave