You can run Webserver on Android for example :
but, there is 2 Case for use with Android Device :
your phone Broadband is how much ?
this Broadband can support users
and online at 24 hours of day ?
this is not good idea for
start webhosting or other something with a Android device.your hardware need backup and set other Options...
and about Questions :
Point me at what to read about this, so I can set it myself
yes you can.use below link :
Tell me if the phone can run only on a charger, without a battery
(because I expect it won't live long if the battery is constantly
i have no idea, But this links maybe can help you :