Does こと mean 'thing' in the following context?

Question

The characters are having the following conversation (provided for context), and I'm unsure as to what こと in the last line means. According to a previously asked question, it has a large number of uses. From the context, I'm tentatively guessing that こと means "thing", seeing as how the topic is about a talent that the first character was previously unaware of. I'm unsure though, as こと has many other uses.

「……才能？」

「あなたには、生まれついての才能があるのよ

人を殺す才能。

生き残る才能。

暗殺者としての才能が」

呆れた話だった。

いきなり何を言いだすかと思えば。

「はは……、わけの解らないこと言わないでくれよ。大体、何の根拠があって……」

Is my understanding of the use of こと in the above sentence correct?

Answer 1

As you say, the こと means “thing” in this sentence.
私には人を殺す才能や生き残る才能などの生まれついての暗殺者としての才能があること is the 意味のわからないこと(nonsense thing).

Answer 2

This こと simply means "(intangible) thing". Simpler examples are:

• 悲しいこと sad thing / something sad
• 嬉しいこと happy thing / something happy
• 簡単なこと easy thing / something easy

Likewise, 訳の分からないこと means "nonsensical/unreasonable thing", which is the object of the verb 言う.

---

In case you don't know what this 訳の is doing, you have to analyze this part as a relative clause. Actually, 訳の分からない is a relative clause modifying こと. So the very literal translation is:

訳の分からないこと = 訳が分からないこと
thing in which reason/logic is not understandable

→ unreasonable/nonsensical thing

This combination appears very often and you may practically think 訳が分からない or 訳の分からない is almost like a single-word i-adjective, as I explained before. Also note that ga-no conversion may happen. Simpler examples of this pattern are:

• 心の狭い人 a narrow-minded person
• カバーが赤い本 a book with a red cover
• 桜の有名な公園 a park that is famous for cherry blossoms

_{By the way, I feel you're asking about almost every single sentence in this scene over several months, and you've asked about the exact same sentence four months ago. This time, こと is one of the most basic words of Japanese. Are you sure you're reading material suitable for your level?}