Like for example the horrendous demands from Warner Brothers for the entire Batman DLC instead of free games. opinions ?

I don't know the deals Sony has with the producers of the games, but if they don't give DLC already maybe it's because it could be more expensive for Sony than just getting the game.

Would instantly piss off a whole bunch of people who do not own said games.

Yeah...that seems like a bad idea.

Including DLC with the actual game would be great, but having DLC instead of stand alone games? I don't think i'd like that much, since i'd be required to buy the actual game to get the most out of my PS+ sub. It could maybe work as a perpetual service though, along side the free games (so having an ever-growing list of games for which the DLC is free if you have PS+). I have no idea how financially practical that would actually be though.

That would be a terrible idea.
But I am still surprised Sony hasn't secured any AAA games to give away for free, as then the gamers would be more likely to buy DLC for them (if you don't have the game, you're certainly not paying $10-20 for DLC).

Games like Assassin's Creed, Shadow of Mordor, Killzone, Watch Dogs.... I am sure that the developers would actually make more money from selling DLC for those games than selling 12-24 month old games.

What i meant is optional subscription offering ps4 multiplayer and dlc instead of games

I was gonna say this, but luckily this was one of the first posts in the thread. DLC and the game the DLC is for could work, but not DLC instead of games.

Would also open a whole new can of worms... so if the PS+ sub runs out, the DLCs get deactivated?

Not many games would be able to handle that, many save games would be corrupted.