1. Dark Souls sold much better than Demon's. Not much else to say.
Sure, Demon's Souls laid the foundation, Dark Souls spring boarded from that to greater success. Obviously multi-plat helped, but a true Demon's Souls 2 likely would have sold far better than the first as well, just like Uncharted 2 and 3 destroyed Uncharted 1 in sales.
2. Maybe, but they're doing good with Namco and Namco would likely influence them to stay.
We don't know how well Namco are treating them and the only real influence they'd have is cash money.
And Sony's long working relationship with FROM is not. Your point?
Wouldn't Namco be able to pay them more money because they can expect higher revenues? I just don't see how Sony could compete when Namco knows they have both a huge hit on their hands and a much larger market they can go after.
Namco needs a profit margin in there for it to be viable, Sony doesn't. Nintendo likely won't see substantial profit after paying off SEGA and funding Bayonetta 2, but they're still making it. How is that more viable for Nintendo than for multi-platform SEGA? Because Nintendo doesn't care if it makes money, they want it to sell systems.
Sony could use Demon's Souls in a similar fashion and Namco won't be able to win a bidding war against that. A guaranteed multi-million seller as an exclusive where you'd also own the IP and have a close partnership with the developer? Seems like a great time to drop an early generation cash bomb, doesn't it?
You ask me a Miyazaki led Demon's Souls 2 within the first 18 month window for the PS4 makes a TON of sense, since Namco Bandai has decided to push Dark Souls 2 out the door for this gen, leaving the next couple years open for a next gen Demon's Souls to steal the limelight.