You can, but one PS4 must be set as primary, this one can play all content offline and on whatever account. The other PS4 can only play online and on the same account that bought the game.

so it has to be online?

can we play at the same time?

I remember this one! 
I enjoyed this game so much back then on PS1 though I only owned the demo. ^^

Yes, Jack Chan Stunmaster is great, played it a freaking lot as well.

PS1 classics are frozen right now, they are only focused on the PS2 remaster/trophy classics for PS4.
Gonna be a while before we start having more PS1 games on the store.

That is like PT, is a promotional piece instead of being like the actual game (in that case, Silent Hills).

That house will be on the game, there is a picture of a helicopter with the symbol of Umbrella and it's confirmed to be a sequel to RE6.
You may want to play the demo again, try to open the switch under the fireplace before watching the video, that key won't be there anymore, then you can find a fuse to give power to the 3rd floor elevator and reach a telephone, which will ring with some info from a woman voice, which may be Ada (hopefully).

It does really not feel like Resident Evil, aside for the puzzles, that's really RE like, you can only find a hand axe but you can't kill anything, but there will be guns and such in the game, you'll pass on that house but the game is expands to way over it.
I was really desperate with what was there and that it won't be RE anymore, but it may still be, the only problem, IMO, is that there is a ghost girl in the house, and RE never had ghosts (RE 4 was originially supposed to have, though, but it was heavily changed), and I don't want RE to mess with this paranormal stuff, RE was always around science in the end, not out of this world stuff. But I'm happy with the news we got after the demo came out, it'll probably still have a RE feeling, even if will be changed quite a lot as well.