yes
no
If you get call of duty black ops there is a zombie mode and you can play it online.(There are other call of duty's with zombie modes.)
The PS3 can only get downloads for games from thePlayStationStore. There is no custom maps available at the store so no there is no custom Zombie Maps. It's a PC thing to mod games with unauthorized software not approved by the copyrighted game developer
I would say ether left 4 dead or left 4 dead 2. It is an awesome game and I recommend buying them.
Combat Arms, sponsored by Nexon, has a game mode called Quarantine Mode where you can play as an Infected Zombie (and infect other humans) or fight as a human and try to stay alive until the game ends.
Multiplayer games are games that you can play with other people
i have a ps3 in my opion multiplayer games are off this planet
Without wi-fi, you can't play online multiplayer on PSVita. But you can still use Media Go! to do system and game updates, and game downloads from the PSN. Plus of course if the game has no multiplayer option, then wi-fi is not necessary there either.
For more there are so many Zombie Survial games to play but the best zombie survival games are Resident Evil 2 State of Decay 2 Project Zomboid and you visit this blog to learn more : newone.games/best-zombie-survival-games/ Best Zombie Survival Games Best Zombie Survival Games
There are many websites which have free online multiplayer games. For instance, Texas Hold'em and the game called Scrabble are multiplayer games and are available to play through websites such as Pop Cap. Game Sheep and Free Arcade also have multiplayer games.
You wouldn't need to go out and buy anything. Google free downloads for your computer that does the same kind of thing that you are looking for. Most of them out there are free.