I agree 100%.
One of the most irritating claims in this campaign is the idea that Biden has always been good, honorable, and decent man. As you pointed out, plagiarism has followed him throughout his career. Not just in college. His 1988 Presidential campaign was derailed by revelations in the press he was "borrowing" from Neil Kinnock, RFK, and Hubert Humphrey in his speeches.
He hasn't merely made comments that appear racist. He wrote the 1994 Crime Bill that filled America's prisons with blacks and Hispanics for simple drug possession.
Add to that his creepy habit of sniffing little girls hair and his daughter's diary confirming he would shower with her up to age twelve. Combined with all the points you make, we must conclude Biden is neither decent nor competent.
*MySmiley*
"Bustin' makes me feel good!"
Ghostbusters, by Ray Parker Jr.