For removing the stripe, you have a free option and a paid option.
Free (and long) option is to use Resource Hacker to open up Dynamic Black.msstyle, find the resource (I would have no idea where the resource would be, or what it would look like), edit it, and replace Dynamic Black.msstyle.
Paid option is to use Ave's Vista Style Builder, open Dynamic Black.msstyle, and find the image and edit it.
Very vague, but I really don't worry about that.
As for the transparency of the taskbar, maybe my program can help?
Check my signature for the link.