Both true, but two types of fraud. The 100% districts are due to some sort of coaching or other system preventing a free vote in unmonitored precincts. The vote also represents lockstep ghetto mentality, I really doubt the actual vote is less than the high 90's. They didn't need to be cautious and didn't overdo some other type of fraud.
The other types of fraud are present almost anywhere and manifest in college students who can vote in their college and home state with almost no way of being caught along, the infirm being coached how to vote, the dead or fictitious voting absentee. That may add up to enough fraud to swing a swing state but I have not seen an analysis of enough extra votes to do that. 1k seems plausible, but not 100k here in Virginia.
Of course not. The analysis has not been done, probably will not be done, will be jumped on as “partisan” if done and an inconvenient result is shown. So this is all speculation and wishful thinking. No sense getting hung up on it. Obama is in, will stay in barring Divine intervention of some sort, and what cannot be remedied must be endured.