Generalized Indiscernibles as Model-complete Theories

We define a mild generalization of classical Fraïssé classes, and in this context, we recover several old (often with novel proofs) and new facts about Ramsey classes and generalized indiscernibles in the sense of [12], [17], and other sources. Of particular novelty are: (1) a new and clearly model-theoretic proof of the equivalence of the Ramsey property and the extreme amenability of the automorphism group of the Fraïssé -limit, and (2) an analysis of the pseudo-finiteness of Ramsey-expandable Fraïssé classes.