2 things i need to know.

[jinglesaw]

How do I take a hostage with the keyboard and is there a godmode?

[Skymirrh]

You need a one-handed gun and then you simply use the execution key (Space) on a knocked down mob to take him as a hostage.
There's no godmode ;)

[Lizard Face]

You can also take a hostage with the double-barrel shotgun.

[Skymirrh]

Цитата допису The Narrator:

You can also take a hostage with the double-barrel shotgun.

...which, as it happens, is a one-handed gun :P