What will be the most appropriate site to ask questions like that:
Is English 'issue' etymologically related to Russian 'ищу'?
I was suggested, that English.SE isn't the best site for such questions, because they are regarding meanings in other languages (in that case, Russian). I don't think that it will be more appropriate on Russian.SE since it is more question about English than Russian. I was informed that such questions are rather off-topic on Linguistics.SE. The Languages proposal is in definition phase on Area51 and doesn't seem to be very popular...
So, if I'm particularly interested in finding relations (common ancestry) between words in various languages, where should I ask them? Should I try, as in that case, to ask on one of the language's SE (if existing) or I should restrain and wait for something like Languages.SE or Etymology.SE to be created?