N00b question about walking speed and physgun

[CrazySwede]

I own a RP server and I have encountered 2 problems.

How do I modify how fast you walk and run?

And when I use my physgun it doesn't grab the things, as if they were not my own stuff. I only
see the blue laser change color as if it grabbed the stuff but I can no lift them or something like that.

I have checked this up if it was a client issue and it was not. There is something about my server because
other players can't use physgun even on their own things as well.

P.S - Sry about my bad English!