By DRM-free I mean not having the same implementation as Xbox One with used games.Now I don't think 3rd parties will blacklist the system because of this, because I don't think they can afford to not develop for it. Large publishers like EA cannot hope to survive on Xbox alone. They're already losing tons of money, how would they do if their game sales got cut in half? Sony may not get as much support as Xbox One with DLC, but they will still get all major releases. They could of course develop for WiiU and Xbox1, but the systems are so far apart in power that it wouldn't be a viable option.

Not at all. Actually Sony is in a position of strength now in wich surveys give the ps4 90% of the next gen market without wii u.
Sony has 3rd parties by the balls after microsofts mess up. No support and your games will fail sales wise because the consumer is gonna be blocking the xone. Theres alot more money to lose by not supporting sony.

No. 3rd parties can't afford not to release their games on PS4, simple as that.

It won't kill 3rd party support, but depending on how well 3rd party companies do on the Xbone then the PS4 could start losing support. Some games will be exclusive to the Xbone, the PS4 could get "bad ports" because devs focus will the on the Xbone, etc.

But in the end 3rd parties can't support only one console, it wouldn't make sense business wise.

No.

what nem said, with the PR disaster that was the xbone reveal sony has a lot of leverage to say no now. if ms was pressured into this arrangement by EA/Activision they also have a lot of leverage to say "not anymore" now.

If they planned to do it first, then changed their mind, then yes.

If they never had any plans to do DRM then no.

nope but it could hurt the vita

Just like online passes, they can always implement full game access passes.
Since Xbox One forces online checks it would be the same for both systems in the end.
And they can still offer their games digitally.

The only reason they may not go there is if they're afraid to lose sales to publishers that won't go this route, and from people that don't connect their console online.

Dev's can make the choice of loosing a larger profit from a entire new game? or loose a small amount from a 2nd hand game, PS4 will be fine.