The function of the word “pouvoir” is that of a verb; it never takes “de” in its constructions; it is almost exclusively followed by a “proposition infinitive”. There are exceptions as in “Qui peut le plus peut le moins.”.

“Parler” really is the infinitive of the verb “parler”, that is it is the word “parler” used as a verb form and not as a noun (as in “Le parler frank n’est pas son fort.”).
“En” is simply put for “Bootstrap Agregating”; the author wants to be able to use this term in French; without the pronoun he would have had to say “L’objectif de cette traduction est de pouvoir parler de (la technique du) « Bootstrap Agregating » dans un papier scientifique en français.”.