BEG is not a third world airport it is just like airports in America or Europe (although a rather old one) So do not worry about using an e-ticket I have used one several times leaving BEG.

I think the airport which would have the most rouble dealing with an e-ticket which I have flown from is Dushanbe (Tajikistan) but then again I do not think that Tajikistan Airlines issues e-tickets.