No. It's not safe to travel to that region alone and if you were trying to get to the country for that sole purpose you'd probably get denied a visa anyway. On a visa application for Russia you have to write the places you're planning to visit - I'm sure they wouldn't even give your application a second look if they saw "Dagestan" or "Chechnya" on it. Also, it's not easy to get a Russian visa because you have to have an invitation (приглашение для иностранев) which would be easier to obtain if you were going with a tour group. Even if you did succeed in getting there, you'd stick out big time because of your skin color and your gender (harsh but true) which would make you a bigger target for tourist-related crime perpetrated both by locals and by the violent rebels that have control of much of the North Caucasus right now.
The fact that you REFUSE to learn any Russian will put you at a huge disadvantage anywhere in the country. The people you'd be trying to interview wouldn't at all appreciate being approached and addressed in English - it's SO disrespectful - and anyway, most people outside of the big cities don't speak that much English (why should they?). Besides all that, it's just not safe to travel to these places unless you REALLY know what you're doing, because the situation is unpredictable. There are military checkpoints everywhere. In Dagestan just last week, there was a shootout between some insurgents and Russian soldiers in which several people died. I hear that there are also special operations there all the time as well as random bombings, kidnappings, and so on by the rebels. There are land mines everywhere,etc. in short, if you go there, something life-changingly horrible WILL happen.
If I were you, I'd just keep my distance from Russia. It sounds like you really know nothing at all about the country or its people. If you really HAVE to go to this part of the world alone, I would try the safer places like Sochi (Сочи) or Gelendzhik (Геленджик) near the Black Sea. Maybe Georgia, Armenia, or Azerbaijan - I bet these places are beautiful and they probably have significant numbers of refugees from the Northern Caucasus.