- A little late, I'm sorry. I don't check blogs often...
But I noticed there were some confusion with the terms Shota, Loli, and Moe... Here're some clarifications.
The exact origins of Moe are unknown, but it means "budding/young, attractive, cute/adorable" and is used to describe characters that are appealing to the senses and some times seem or are young. Moe is said to originate from either Sailor Moon and/or Kyoryu Wakusei. Neither series are hentai, ecchi, or anything for audiences above 15. In fact, Sailor Moon is a shoujo series, not seinen or josei and for audiences under 16 [nowadays it's considered for 13 and under], and Kyoryu Wakusei is a kodomo [for children 10 and under] series. It did not have adult origins but infact origins from manga directed towards younger audiences. It still doesn't always refer to characters from adult series.
It originates from the book Lolita by Vladimir Nabokov. [Great book, btw] In terms of the book, Lolita [from the name Dolores, shortened to Lolita then Loli] would mean a younger girl attracting an older man with trickery, considering how Lolita lured Humbert with sexual favors to get money from him. But when the term Lolita traveled to Japan, it means the Victorian fashion where girls would wear Victorian era clothes and would look cute and young. Lolita later became lolicon , which is a sexual infaturation with significantly younger girls or girls than look very young [lolita + complex portmanteu]. But then the word loli came about. [Note that loli is almost never used in Japanese culture unless it's lolita or lolicon. It is more often used overseas than in Japan. Sometimes in anime and manga loli would be used in place for lolicon, but that's very, very rare. The only time I remember loli being used is when NNDic descrived Kano's voice as loli, but that had no mature meanings behind it. It just meant that she sounded young.] Loli would mean that the girl either seems younger than she is or is very young. In this case, loli came from a mature material source. [Though, I somewhat disagree since the book Lolita is sexualized, but it's heavily disguised. I read it last year when I was 14 and I wasn't "deranged" by it or anything.]
Shota came from the series Tetsujin 28-go/Gigantor, where the protagonist's name is Shotaro and he is a young boy. Shota doesn't have mature origins because Gigantor is a kodomo series. Shota later on became Shotacon [shotaro + complex portmanteu], which refers to a sexual attraction for underaged boys or guys that look young. Later, shota seperated and became a word on it's own, much like loli. Shota came to mean a seemingly young guy or a really young boy. Likewise, shota is used more overseas and very rarely used in Japan. The only time I remember shota being used by a Japanese was in Suteki Tantei Labyrinth where Minori said "Sho-sho-shota!?" when she discovered that she had feelings for the protagonist Mayuki, who was the same age as her though he looked like he was several years younger.
So evidently, only Loli had actual mature origins. Moe and Shota can refer to mature connotations, but not always. Loli and Shota very rarely refer to their mature meanings, Lolicon and Shotacon. Moe can have mature meanings only if the user finds mature subjects appealing. [I've heard people say guro is moe... So it's highly subjective.]
In terms of Utaite, you can use them to describe voices. You can say that, for instance, Kony's voice is both shota [Rimokon called Kony's voice shota because he sounds like a little boy] and moe [because I find his voice appealing and I think he sounds younger than he really is]. Lon sounds like a shota because her voice sounds like a little boy's voice. Kano sounds like a loli because her voice sounds like a young girl's voice. In no way can loli or shota be used in place of trap/ryouseirui.