I came across your sight while searching for information about the abandoned house on the grounds of Borromeo.
It IS haunted, I am quite sure of it. We used to walk by it when I was a kid. This was between 1981 and 1983. Images of the place flash in my memory from time to time and I have nightmares about the grounds of All Saints. Something very strange happened to me there which I still cannot explain and I suspect something latched onto me and has bothered me for my entire life. The story is that I was found walking around the grounds of the school in a state of shock. I don't remember walking around, I just remember waking up in the nurses office. I thought I had been knocked out because I opened my eyes on the cot. None of the other kids knew what happened to me. I have flashes of memories of dark figures standing above me and there being tall brown grass around me (I think it was at the top of the hill where the statues are). I've wanted to go back to the grounds to try to recall what happened since it's bothered me for my entire life, but at the same time, it might be something I don't want to know.
Anyway, yes, it is haunted and there is something terribly evil about that place. Be careful if you go there.
Since this is along your lines, look at the grounds of the seminary from above on google maps. Note the significance of the owl in occult symbolism.
That is all.