A.) Do not worry so much about this. You will safely arrive if you have hope, and be very careful not to make a mistake. I don't really know how to answer you on this one but just be sure to ask for help if you need it!
b.) Ohhh nooo! Prejudice is in human nature but do not worry at all about that. Don't care what other people think of you; it is their choice to be judge-mental and rude so don't care about them whatsoever, but I even doubt you will be racially judged.
C.) If it is a tolerant/public school then you also need not to worry about this. You can tell people if you want or don't tell people if you don't want to, but if the school is public and open then I am also doubtful about anything bad happening.
D.) Many places in the world including Russia teach English, and especially in universities people will likely know English so if you are good at English then you should have no problem. But might I ask, are your classes in English? Because you will have to understand your studies
E.) I don't think you'll be forced to participate. I'm not very eloquent in these matters since I have not yet reached your level but it entirely depends on the school.
And if you really don't want to study abroad, then tell your parents about it! OR better yet, you will be 18 so you can make any choice for college you want. Do what will be best for you. It is good to let your parents be an influence, but don't let them be your decision-makers.