In the 1840 edition the infinitival to was deleted before the verb cast near the end of this passage. This deletion was undoubtedly accidental since otherwise in the text there are numerous examples of conjoined infinitival clauses; in fact, earlier in this passage, we have one, namely “for to lie and to deceive this people”.
This passage also has a case of the archaic or dialectal for to, a usage that Joseph Smith generally removed from the text in his editing for the 1837 edition but not here in Alma 12:4. There is one other place in the text where for to remains, in Mosiah 13:25. For discussion, see under that passage as well as under Mosiah 20:1; also see the complete analysis under for to in volume 3.
Summary: Retain in Alma 12:4 the repeated infinitival to in the conjoined infinitival clauses (“to revile us and to cast us out”); also maintain the use of for to in this passage (and elsewhere in the text, whenever it is supported by the earliest textual sources).