What do the following from output of sh run refer to?
no service pad
Yes if you're not using X.25, disable PAD.
service tcp-keepalives-in is to the router management plane, not traffic going through the router. Here's a common example; You telnet into a router and do some work. Instead of logging off the router you just close your terminal application. The router thinks your still connected and is waiting for input. If you do that enough times, you'll use up all your VTY lines and you won't be able to access the router via telnet. With service tcp-keepalives-in the router will timeout the session after inactivity ensuring you always have a VTY line available.
Hope that helps