As for the order of things:
"In conditional statements, the conditional clause precedes the conclusion as the normal order in all languages. (...) (Greenberg 1963: 84, #14)
As for the question if there are words for "if", "then" and "else" in all languages: No idea, maybe someone else can answer. My guess would be, no. See also jk's comment that in German, the conjunctive makes the word "if" redundant. In English, you could also say: "Had they told me this, ..." instead of "If they had told me this, then ...". You can surely leave away "then" in these two languages, and replace "else" with "or". I think that we are entering pragmatics territory here, meaning it's not only logic and compositional semantics, but also their actual (conventionalized) interpretation.
Greenberg, Joseph H. (1963).
Some universals of grammar, with particular reference to the order of meaningful elements. In Greenberg (ed.) 1963, 73-113. Greenberg, Joseph H. (1964 [1965, 1978e]). Some generalizations concerning initial and final consonant sequences (Russian) Voprosy jazykoznanija 1964-4, 41-65. Translated in Linguistics 18: 5-34. Also published in Greenberg (ed.) 1978, Volume 2, 243-279.