- Relative clauses can be very long both in English and Japanese. In your second example, "採集自体よりも殺虫瓶のなかの青酸カリに魅せられて、どうしても足を洗うことが出来なくなった" modifies 者 as a relative clause.
- Most Japanese sentences end with a verb, but sentences that end with a noun are relatively common. It's a type of rhetoric device called 体言止め. See: what exactly is "体言止{たいげんど}め"?what exactly is "体言止{たいげんど}め"? Making sentences 体言止め makes them more vivid, rhythmical, compact, etc. In your case, I feel 体言止め is used for the sake of brevity, so you can simply translate it as if it were a normal sentence (ie "伊藤 is also selected as ...").