for question #3,
Are you currently running XP or Vista?
if it's XP , and you want to see transparency , I think the problem might be in windowblinds config.
if you have the setting in "transparency and blur" set to "vista-ize me" it should show transparency in your skins. I have it set to all skins on my computer, and only disable it when the skin really needs to be opaque, (like the "beer" blind).
sorry if this doesn't help, I'm not actually a skinner, just a skin user. but it could be a possibility that you aren't seeing transparency on your computer because it isn't clicked to be so.
if you're a Vista user,... disregard anything I just said... it's a moot point.