Point 1: as I stated, this is the only thing that sways the verdict towards him being local.There a plenty of reasons to think the Ripper was a local.
* As you note, serial killers tend to start off close to home.
* Both times that he was interrupted, the Ripper did not just "move on quickly and walk down the street", he was not even seen walking away. That might be mere luck, but it is more likely the Ripper was very familiar with the area.
^ After he was interrupted in the mutilation of Stride, the Ripper knew the areas well enough to reach the Mitre Square in time to kill Eddowes.
* Part of Eddowes' apron was found in Ghoulston Street, which was still in the area.
* The killer took organs from Chapman, Eddowes, and Kelly. Being caught with these 'trophies' would be even harder to explain than bloodstains, so odds are the Ripper didn't have to travel very far before reaching his lodging.
* Chapman was killed within an hour of sunrise, probably within half an hour, so the killer had to live close enough to get home before sunrise.
Point 2: we don't know what he did, and how quickly he moved, except it was a good 20 minutes after the murders before the police organised a search. So, unless he thought it was a good idea to hang around doing cart wheels around the murder site, he would have been long gone. And, of course he was seen walking away, he simply wasn't connected to the murder. The East End wasn't a warren of hidden doors within hidden alleys where people could avoid the general populace. He had to walk down streets just as he would today.
Point 3: he's walking away from the murder scene, so when he drops the apron it has to be in some area directly leading away from the murder scene.
Point 4: 'odds are that no one is going to ask a bloke walking down the street for a look at what he has in his coat. I've walked miles and no one has ever come up to me and asked to see what I have under my coat. I'd imagine it's the case with about 100% of the world's population. So, it's fair to say he had nothing to worry about on that score and he could quite easily feel comfortable walking a long way in that situation.
Point 5: walking 'round in those days with blood on your person is not what it is now. It was part and parcel of day to day life then.