I have a pretty good grasp of grammar/spelling, so I'm happy to fix up any problems there. I'll only change plots or characterization if the story doesn't read well without the changes. I believe each writer has their own ideas about this - I don't see why I should impose my ideas on others. I'm not so keen on editing BDSM stuff - it's not my thing so others will have far greater knowledge about it. I'm willing to give pretty much anything else a try though.