Well as long as you can figure some stuff out I'd say you'd probably be able to release a highly wanted beta, but if RMXP scripting is different than ROM scripts(and I have no doubt in my mind that it is), then I am utterly clueless on that matter.
And yeah, if you're having that much trouble, I'd suggest asking an experienced scripter, at least so they can teach you how to add what you want, like Poison fog.
BTW have you ever thought about having Poison fog poison the player's Pokemon?