Re: Edge iii tuning stability problem
Well, even if you follow all setup advice perfectly, your trem will most probably not stay in tune. The Edge III is well known for this problem. It's a low cost/low quality system and many guitarists change it for a better one, because the RGs are otherwise perfectly well operating guitars and definitely worth the additional costs for the modification with a better trem.
The first thread in this section is about which trem to choose for replacement.
I just did the same on my RG 350 MYE, a very useable guitar with Edge III tremolo. I had it replaced with an Edge LoPro just a couple of days ago and it's very satisfying.
Maybe I'll change the pickups later as well, but they're not bad. I like Evolutions and maybe I'll do it next year.