People will understand you just like they understand people from Spain. Also, Russian speakers usually have problems with V/W and the French vowels (Russian has five vowels and International French has 14 vowels). Good luck learning French!

Bonjour When a Russian speaks French fluently, this is generally the last thing that betrays his origin. Old habits die hard. So, I think that the pronunciation of ‘r’ should be in the first lessons. You can get help from a native. Just for fun, note that the pronunciation of Russian ‘P’ (a bit emphasized) is the means by which humorists suggest a Russian character.

Hi! For sure, it is acceptable because the first goal of communication is to exchange with others. It is a similar sound, but not exactly the same, so the meaning of words is not really changed. So, in that case, the impact is not really big. The way you prononce the r will give an impression of accent. I don't know the Russian language, but I've read that the r is prononced with the tip of the tongue. In French, it is prononced with the back of the tongue, in the back of the mouth. The feeling is a little bit like when you gargle your mouth.

Don't worry about that ! A large part of frenchpeople pronounce it in that way, espescially people from the southwest of France. So you can say you come from the southwest of France. If you want looking like a parisian girl that will be different.

Здравствуйте ! Французский "р" он находится далеко в горле и похоже немного на русские людей которие картавить ! Он глубоко в горле как русский "х". А так с акцентом прикольный