Disclaimer: I'm a native speaker in the sense of being born & raised (& schooled) in the US, but my first language was actually Hungarian. My parents have a well-justified distaste for All Things Soviet, which the last 20 years have not erased. So my reactions are perhaps not typical.
The origin of "comrade" and the justification (or lack thereof) for its Communist associations is, I think, largely irrelevant. The fact remains, there is such an association. It might be looked upon as "antique" by younger generations, but it has not gone away. Bottom line: I would not suggest using the word "comrade" as a generic synonym for "friend".
Camaraderie, for whatever reason, does not carry any Cold War-era connotations that I know of in English. (I think it might in German.)
tovarishch
is not actually a borrowing of comrade, but an approximation (that is then translated back to English as comrade?)? Or is the word comrade itself used? And if you explain why the Russians started using [word], I think you should feel free to put it in as an answer (as the wiki article doesn't entirely explain the why, only the happenstance).