Console commands and hammer

While testing some things in hammer and ingame I noticed that sv_gravity hinders gordons ability to jump and it doesn’t seem to work on props either. In hammer the trigger_gravity does work, but only seems to work on the player, not on props (with the everythibg flag checked). Why?

The hl2 player speed commands are missing, are there any other command that I could use to increase the speed of the player? The hammer editor player_speedmod only goes up to about 250% faster.