This has been an ongoing problem in one of my fandoms since before I started roleplaying it according to one of my few good RP buddies, so here goes a letter form rant...
Dear Saiyuki RPers,
Hi, it's been forever since we spoke and that is because I need room to breathe. I would not exactly put us in the category of 'good speaking terms' right now. The reason for this is your blatant insistence on a ton of extremely stupid notions that make no sense whatsoever in context and a ton of characterization fail and just general fail.
Okay, let us begin with characterization. You are the reason I prefer not to use the terms 'seme' and 'uke'. You don't seem to realize that the connotation most sane yaoi RPers use is 'top' and 'bottom' not 'man' and 'woman'. Because yes, theoretically speaking, someone like Hakkai or Gojyo could top someone like Sanzo, even in consensual relationships a power struggle is likely, particularly between Gojyo and Sanzo. However your insistence that the 'uke' should be reduced to a giggly subby teenage girl is ridiculous and irritating.
You see, I just have a really hard time imagining Sanzo wearing girl panties and being all feminine and shy. It occurs to me he'd be more likely to pull his gun or punch someone at the first feeling of discomfort or regret. Also with Gojyo's constant insistence that he is, infact, straight, I feel like being blatantly romantic and touchy feely with, say, Sanzo for instance, is completely out of character.
On the subject of out of character, I'd also like to bring up your love of crack pairings that won't work no matter what way you slice it. I am sorry, but if we are roleplaying a scenario after the team first meets Hazel, it doesn't make sense for Gojyo to be lusting after him. Infact, it's completely insane. Hazel hates demons and half-breeds. Gojyo is a half-breed. IT WOULDN'T WORK. Also, Gojyo thinks Hazel is an obnoxious asshole. If you want to make the characters that OOC for your wish fulfillment, write a fanfic, I intend to play Hazel as he is written or else he isn't Hazel.
Then there's the Mary Sues...well...Marty Stus since it's usually yaoi RPs. You're not fooling anyone by taking pics from a different anime, especially if the file you send or the image you link to blatantly says 'AXIS POWERS HETALIA JAPAN' also, you aren't good at recolours. I can tell from the shoddy edit work that you recoloured the character. Not to mention, most of the anime watching population has seen, read or at least heard of Fullmetal Alchemist, Kuroshitsuji and Axis Powers Hetalia. Yes, that's right, your recolour of Ed, Ciel or Japan isn't fooling me or anyone else. Of course, I wouldn't mind so much if you'd ADMIT that you were basing the appearance off them and if you were actually a competent RPer who didn't just want to touch yourself to the mental image of hot Saiyuki bishounen sexing your Stu.
Finally, your aversion to any dark subject matter but the fact that you seem to love Mpreg so much. So what? Murder, occasional angst and an RP without romance upsets you but the image of Goku popping little halfbreeds out his ass does not? Ugh...I have no more words. I need a friggin drink. Oh, and on a final note, I have met literally three Saiyuki RPers who actually bother to type out a reply any longer than 'He giggled and kissed Sanzo.' Really? That's all you've got? Just....Head. Effing. Desk.
Sincerely,
A very annoyed Hazel RPer
TL;DR: For a pretty good series, the fandom seems to by and large lack the ability to RP in so many ways.