I do think Repin is excellent and if possible I would study there myself.
Everything depends on your direction. You may create bad habits, but maybe one persons bad habits becomes another persons way of expressing his or herself. Many good artists exist throughout the world who have never attended the Repin academy. I studied under Robert Liberace this summer for a week and I personally think he is extremely skilled. Besides him I enjoy Richard Schmid and many other painters in the US.
Yes, I agree it is extremely important to have a strong base to stand on, but many places can offer that. Not to mention the world is full of excellent books on art to help you build that base. The most important thing is practicing drawing and painting from life. That is the only way to build a strong base. It doesn't need to be in any particular place. I think it helps to be surrounded by artists who are passionate and better than you. Even as a professional that kind of environment will only benefit you.
That sounds great, but I would try pushing for days that are Dec 10-22 or June-August. This would allow currently studying students to attend as well. I would be very interested in attending myself, but I think I cannot afford it. When you get some prices please let us know so I can attempt to save. Also, if you are interested in having a workshop in the US I can connect you with a few places in Florida.