Nope, e2 has no function for that. You can always control them, though.
Chat with our AI personalities
No. Unless it's a glitch, the only way you can spawn them other then mods or console is going into the NPCs section and manually spawning a zombie.
yes
no because garrys mod requires that you have a game that uses the source engine
gmod is 10$ at garrysmod.com
You have to build one.